Clean up null issues, add more annotations (#3590)

patches/minecraft/net/minecraft/block/BlockFlowerPot.java.patch

@@ -36,7 +36,7 @@
 +        return super.removedByPlayer(state, world, pos, player, willHarvest);
 +    }
 +    @Override
-+    public void func_180657_a(World world, EntityPlayer player, BlockPos pos, IBlockState state, TileEntity te, ItemStack tool)
++    public void func_180657_a(World world, EntityPlayer player, BlockPos pos, IBlockState state, @Nullable TileEntity te, ItemStack tool)
 +    {
 +        super.func_180657_a(world, player, pos, state, te, tool);
 +        world.func_175698_g(pos);

patches/minecraft/net/minecraft/block/state/BlockStateContainer.java.patch

@@ -8,7 +8,7 @@
 +        this(p_i45663_1_, p_i45663_2_, null);
 +    }
 +
-+    protected StateImplementation createState(Block block, ImmutableMap<IProperty<?>, Comparable<?>> properties, ImmutableMap<net.minecraftforge.common.property.IUnlistedProperty<?>, com.google.common.base.Optional<?>> unlistedProperties)
++    protected StateImplementation createState(Block block, ImmutableMap<IProperty<?>, Comparable<?>> properties, @Nullable ImmutableMap<net.minecraftforge.common.property.IUnlistedProperty<?>, com.google.common.base.Optional<?>> unlistedProperties)
 +    {
 +        return new StateImplementation(block, properties);
 +    }

patches/minecraft/net/minecraft/entity/monster/EntityZombieVillager.java.patch

@@ -8,10 +8,11 @@
      }
  
      public int func_190736_dl()
-@@ -85,6 +86,19 @@
+@@ -85,6 +86,21 @@
          return super.func_180482_a(p_180482_1_, p_180482_2_);
      }
  
++    @Nullable
 +    private net.minecraftforge.fml.common.registry.VillagerRegistry.VillagerProfession prof;
 +    public void setForgeProfession(net.minecraftforge.fml.common.registry.VillagerRegistry.VillagerProfession prof)
 +    {
@@ -19,6 +20,7 @@
 +        this.func_190733_a(net.minecraftforge.fml.common.registry.VillagerRegistry.getId(prof));
 +    }
 +
++    @Nullable
 +    public net.minecraftforge.fml.common.registry.VillagerRegistry.VillagerProfession getForgeProfession()
 +    {
 +        return this.prof;

patches/minecraft/net/minecraft/tileentity/TileEntityBrewingStand.java.patch

@@ -65,7 +65,7 @@
 +
 +    @SuppressWarnings("unchecked")
 +    @Override
-+    public <T> T getCapability(net.minecraftforge.common.capabilities.Capability<T> capability, net.minecraft.util.EnumFacing facing)
++    public <T> T getCapability(net.minecraftforge.common.capabilities.Capability<T> capability, @javax.annotation.Nullable net.minecraft.util.EnumFacing facing)
 +    {
 +        if (facing != null && capability == net.minecraftforge.items.CapabilityItemHandler.ITEM_HANDLER_CAPABILITY)
 +        {

patches/minecraft/net/minecraft/tileentity/TileEntityChest.java.patch

@@ -16,7 +16,7 @@
 +
 +    @SuppressWarnings("unchecked")
 +    @Override
-+    public <T> T getCapability(net.minecraftforge.common.capabilities.Capability<T> capability, net.minecraft.util.EnumFacing facing)
++    public <T> T getCapability(net.minecraftforge.common.capabilities.Capability<T> capability, @Nullable net.minecraft.util.EnumFacing facing)
 +    {
 +        if (capability == net.minecraftforge.items.CapabilityItemHandler.ITEM_HANDLER_CAPABILITY)
 +        {

patches/minecraft/net/minecraft/tileentity/TileEntityFurnace.java.patch

@@ -107,7 +107,7 @@
 +
 +    @SuppressWarnings("unchecked")
 +    @Override
-+    public <T> T getCapability(net.minecraftforge.common.capabilities.Capability<T> capability, net.minecraft.util.EnumFacing facing)
++    public <T> T getCapability(net.minecraftforge.common.capabilities.Capability<T> capability, @javax.annotation.Nullable net.minecraft.util.EnumFacing facing)
 +    {
 +        if (facing != null && capability == net.minecraftforge.items.CapabilityItemHandler.ITEM_HANDLER_CAPABILITY)
 +            if (facing == EnumFacing.DOWN)

patches/minecraft/net/minecraft/util/registry/RegistryNamespacedDefaultedByKey.java.patch

@@ -7,8 +7,8 @@
 +
 +    //Bypass functions to allow querying this registry WITHOUT getting the defaulted value.
 +    // MODDERS DO NOT USE THIS IS FOR FORGE INTERNAL CHECKS
-+    public int getIDForObjectBypass(V bypass) { return super.func_148757_b(bypass); }
-+    public K getNameForObjectBypass(V value) { return super.func_177774_c(value); }
-+    public V getObjectBypass(K name) { return super.func_82594_a(name); }
-+    public V getObjectByIdBypass(int id){ return super.func_148754_a(id); }
++    public int getIDForObjectBypass(@Nullable V bypass) { return super.func_148757_b(bypass); }
++    @Nullable public K getNameForObjectBypass(V value) { return super.func_177774_c(value); }
++    @Nullable public V getObjectBypass(K name) { return super.func_82594_a(name); }
++    @Nullable public V getObjectByIdBypass(int id){ return super.func_148754_a(id); }
  }

patches/minecraft/net/minecraft/world/chunk/storage/RegionFile.java.patch

@@ -1,8 +1,8 @@
 --- ../src-base/minecraft/net/minecraft/world/chunk/storage/RegionFile.java
 +++ ../src-work/minecraft/net/minecraft/world/chunk/storage/RegionFile.java
-@@ -97,6 +97,39 @@
- 
-     @Nullable
+@@ -95,6 +95,39 @@
+         }
+     }
  
 +    // This is a copy (sort of) of the method below it, make sure they stay in sync
 +    public synchronized boolean chunkExists(int x, int z)
@@ -37,6 +37,6 @@
 +        return false;
 +    }
 +
+     @Nullable
+ 
      public synchronized DataInputStream func_76704_a(int p_76704_1_, int p_76704_2_)
-     {
-         if (this.func_76705_d(p_76704_1_, p_76704_2_))

src/main/java/net/minecraftforge/classloading/FMLForgePlugin.java

@@ -24,6 +24,8 @@ import java.util.Map;
 
 import net.minecraftforge.fml.relauncher.IFMLLoadingPlugin;
 
+import javax.annotation.Nullable;
+
 public class FMLForgePlugin implements IFMLLoadingPlugin
 {
     public static boolean RUNTIME_DEOBF = false;
@@ -42,6 +44,7 @@ public class FMLForgePlugin implements IFMLLoadingPlugin
     }
 
     @Override
+    @Nullable
     public String getSetupClass()
     {
         return null;

src/main/java/net/minecraftforge/client/ClientCommandHandler.java

@@ -134,7 +134,7 @@ public class ClientCommandHandler extends CommandHandler
             if (mc.currentScreen instanceof GuiChat)
             {
                 List<String> commands = getTabCompletions(mc.player, leftOfCursor, mc.player.getPosition());
-                if (commands != null && !commands.isEmpty())
+                if (!commands.isEmpty())
                 {
                     if (leftOfCursor.indexOf(' ') == -1)
                     {

src/main/java/net/minecraftforge/client/EnumHelperClient.java

@@ -24,6 +24,8 @@ import net.minecraft.world.GameType;
 import net.minecraft.client.settings.GameSettings.Options;
 import net.minecraftforge.common.util.EnumHelper;
 
+import javax.annotation.Nullable;
+
 public class EnumHelperClient extends EnumHelper
 {
     private static Class<?>[][] clientTypes =
@@ -33,16 +35,19 @@ public class EnumHelperClient extends EnumHelper
         {EnumOS.class}
     };
 
+    @Nullable
     public static GameType addGameType(String name, int id, String displayName, String shortName)
     {
         return addEnum(GameType.class, name, id, displayName, shortName);
     }
 
+    @Nullable
     public static Options addOptions(String name, String langName, boolean isSlider, boolean isToggle)
     {
         return addEnum(Options.class, name, langName, isSlider, isToggle);
     }
 
+    @Nullable
     public static Options addOptions(String name, String langName, boolean isSlider, boolean isToggle, float valMin, float valMax, float valStep)
     {
         return addEnum(Options.class, name,
@@ -50,11 +55,13 @@ public class EnumHelperClient extends EnumHelper
                 langName, isSlider, isToggle, valMin, valMax, valStep);
     }
 
+    @Nullable
     public static EnumOS addOS2(String name)
     {
         return addEnum(EnumOS.class, name);
     }
 
+    @Nullable
     private static <T extends Enum<? >> T addEnum(Class<T> enumType, String enumName, Object... paramValues)
     {
         return addEnum(clientTypes, enumType, enumName, paramValues);

src/main/java/net/minecraftforge/client/event/RenderPlayerEvent.java

@@ -25,6 +25,8 @@ import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.item.ItemStack;
 import net.minecraftforge.event.entity.player.PlayerEvent;
 
+import javax.annotation.Nonnull;
+
 public abstract class RenderPlayerEvent extends PlayerEvent
 {
     private final RenderPlayer renderer;
@@ -99,8 +101,9 @@ public abstract class RenderPlayerEvent extends PlayerEvent
     {
         private int result = -1;
         private final int slot;
+        @Nonnull
         private final ItemStack stack;
-        public SetArmorModel(EntityPlayer player, RenderPlayer renderer, int slot, float partialTick, ItemStack stack)
+        public SetArmorModel(EntityPlayer player, RenderPlayer renderer, int slot, float partialTick, @Nonnull ItemStack stack)
         {
             super(player, renderer, partialTick, 0D, 0D, 0D);
             this.slot = slot;
@@ -126,6 +129,7 @@ public abstract class RenderPlayerEvent extends PlayerEvent
             return slot;
         }
 
+        @Nonnull
         public ItemStack getStack()
         {
             return stack;

src/main/java/net/minecraftforge/client/event/RenderSpecificHandEvent.java

@@ -6,7 +6,6 @@ import net.minecraftforge.fml.common.eventhandler.Cancelable;
 import net.minecraftforge.fml.common.eventhandler.Event;
 
 import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
 
 /**
  * This event is fired on the {@link net.minecraftforge.common.MinecraftForge#EVENT_BUS}
@@ -22,6 +21,7 @@ public class RenderSpecificHandEvent extends Event
     private final float interpolatedPitch;
     private final float swingProgress;
     private final float equipProgress;
+    @Nonnull
     private final ItemStack stack;
 
     public RenderSpecificHandEvent(EnumHand hand, float partialTicks, float interpolatedPitch, float swingProgress, float equipProgress, @Nonnull ItemStack stack)

src/main/java/net/minecraftforge/client/event/RenderTooltipEvent.java

@@ -4,7 +4,6 @@ import java.util.Collections;
 import java.util.List;
 
 import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
 
 import net.minecraft.client.gui.FontRenderer;
 import net.minecraft.item.ItemStack;
@@ -26,6 +25,7 @@ import net.minecraftforge.fml.common.eventhandler.Event;
  */
 public abstract class RenderTooltipEvent extends Event
 {
+    @Nonnull
     protected final ItemStack stack;
     protected final List<String> lines;
     protected int x;
@@ -42,7 +42,7 @@ public abstract class RenderTooltipEvent extends Event
     }
 
     /**
-     * @return The stack which the tooltip is being rendered for. As tooltips can be drawn without itemstacks, this return is {@link Nullable}. 
+     * @return The stack which the tooltip is being rendered for. As tooltips can be drawn without itemstacks, this stack may be empty.
      */
     @Nonnull
     public ItemStack getStack()
@@ -98,7 +98,7 @@ public abstract class RenderTooltipEvent extends Event
         private int screenHeight;
         private int maxWidth;
 
-        public Pre(@Nullable ItemStack stack, @Nonnull List<String> lines, int x, int y, int screenWidth, int screenHeight, int maxWidth, @Nonnull FontRenderer fr)
+        public Pre(@Nonnull ItemStack stack, @Nonnull List<String> lines, int x, int y, int screenWidth, int screenHeight, int maxWidth, @Nonnull FontRenderer fr)
         {
             super(stack, lines, x, y, fr);
             this.screenWidth = screenWidth;
@@ -181,7 +181,7 @@ public abstract class RenderTooltipEvent extends Event
         private final int width;
         private final int height;
         
-        public Post(@Nullable ItemStack stack, @Nonnull List<String> textLines, int x, int y, @Nonnull FontRenderer fr, int width, int height)
+        public Post(@Nonnull ItemStack stack, @Nonnull List<String> textLines, int x, int y, @Nonnull FontRenderer fr, int width, int height)
         {
             super(stack, textLines, x, y, fr);
             this.width = width;
@@ -210,7 +210,7 @@ public abstract class RenderTooltipEvent extends Event
      */
     public static class PostBackground extends Post 
     {
-        public PostBackground(@Nullable ItemStack stack, @Nonnull List<String> textLines, int x, int y, @Nonnull FontRenderer fr, int width, int height)
+        public PostBackground(@Nonnull ItemStack stack, @Nonnull List<String> textLines, int x, int y, @Nonnull FontRenderer fr, int width, int height)
             { super(stack, textLines, x, y, fr, width, height); }
     }
 
@@ -219,7 +219,7 @@ public abstract class RenderTooltipEvent extends Event
      */
     public static class PostText extends Post
     {
-        public PostText(@Nullable ItemStack stack, @Nonnull List<String> textLines, int x, int y, @Nonnull FontRenderer fr, int width, int height)
+        public PostText(@Nonnull ItemStack stack, @Nonnull List<String> textLines, int x, int y, @Nonnull FontRenderer fr, int width, int height)
             { super(stack, textLines, x, y, fr, width, height); }
     }
 }

src/main/java/net/minecraftforge/client/model/ForgeBlockStateV1.java

@@ -30,6 +30,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
 
+import javax.annotation.Nullable;
 import javax.vecmath.AxisAngle4d;
 import javax.vecmath.Matrix4f;
 import javax.vecmath.Quat4f;
@@ -218,7 +219,7 @@ public class ForgeBlockStateV1 extends Marker
             return ret;
         }
 
-        private Multimap<String, ForgeBlockStateV1.Variant> getPermutations(List<String> sorted, Map<String, Map<String, ForgeBlockStateV1.Variant>> base, int depth, String prefix, Multimap<String, ForgeBlockStateV1.Variant> ret, ForgeBlockStateV1.Variant parent)
+        private Multimap<String, ForgeBlockStateV1.Variant> getPermutations(List<String> sorted, Map<String, Map<String, ForgeBlockStateV1.Variant>> base, int depth, String prefix, Multimap<String, ForgeBlockStateV1.Variant> ret, @Nullable ForgeBlockStateV1.Variant parent)
         {
             if (depth == sorted.size())
             {

src/main/java/net/minecraftforge/client/model/ItemLayerModel.java

@@ -24,6 +24,7 @@ import java.util.BitSet;
 import java.util.Collection;
 import java.util.List;
 
+import javax.annotation.Nullable;
 import javax.vecmath.Matrix4f;
 import javax.vecmath.Vector4f;
 
@@ -140,7 +141,7 @@ public final class ItemLayerModel implements IRetexturableModel
         private final boolean isCulled;
         private final ItemOverrideList overrides;
 
-        public BakedItemModel(ImmutableList<BakedQuad> quads, TextureAtlasSprite particle, ImmutableMap<TransformType, TRSRTransformation> transforms, ItemOverrideList overrides, IBakedModel otherModel)
+        public BakedItemModel(ImmutableList<BakedQuad> quads, TextureAtlasSprite particle, ImmutableMap<TransformType, TRSRTransformation> transforms, ItemOverrideList overrides, @Nullable IBakedModel otherModel)
         {
             this.quads = quads;
             this.particle = particle;

src/main/java/net/minecraftforge/client/model/ModelDynBucket.java

@@ -75,10 +75,13 @@ public final class ModelDynBucket implements IModel, IModelCustomData, IRetextur
 
     public static final IModel MODEL = new ModelDynBucket();
 
+    @Nullable
     private final ResourceLocation baseLocation;
+    @Nullable
     private final ResourceLocation liquidLocation;
+    @Nullable
     private final ResourceLocation coverLocation;
-
+    @Nullable
     private final Fluid fluid;
     private final boolean flipGas;
 
@@ -87,7 +90,7 @@ public final class ModelDynBucket implements IModel, IModelCustomData, IRetextur
         this(null, null, null, null, false);
     }
 
-    public ModelDynBucket(ResourceLocation baseLocation, ResourceLocation liquidLocation, ResourceLocation coverLocation, Fluid fluid, boolean flipGas)
+    public ModelDynBucket(@Nullable ResourceLocation baseLocation, @Nullable ResourceLocation liquidLocation, @Nullable ResourceLocation coverLocation, @Nullable Fluid fluid, boolean flipGas)
     {
         this.baseLocation = baseLocation;
         this.liquidLocation = liquidLocation;

src/main/java/net/minecraftforge/client/model/ModelLoader.java

@@ -121,6 +121,8 @@ import com.google.common.collect.Multimap;
 import com.google.common.collect.Multimaps;
 import com.google.common.collect.Sets;
 
+import javax.annotation.Nonnull;
+
 public final class ModelLoader extends ModelBakery
 {
     private final Map<ModelResourceLocation, IModel> stateModels = Maps.newHashMap();
@@ -1167,7 +1169,7 @@ public final class ModelLoader extends ModelBakery
         ModelLoader.setCustomMeshDefinition(item, new ItemMeshDefinition()
         {
             @Override
-            public ModelResourceLocation getModelLocation(ItemStack stack)
+            public ModelResourceLocation getModelLocation(@Nonnull ItemStack stack)
             {
                 return ModelDynBucket.LOCATION;
             }

src/main/java/net/minecraftforge/client/model/MultiLayerModel.java

@@ -22,6 +22,7 @@ package net.minecraftforge.client.model;
 import java.util.Collection;
 import java.util.List;
 
+import javax.annotation.Nonnull;
 import javax.vecmath.Matrix4f;
 
 import net.minecraft.block.state.IBlockState;
@@ -177,6 +178,7 @@ public final class MultiLayerModel implements IModelCustomData
             return builder.build();
         }
 
+        @Nonnull
         @Override
         public List<BakedQuad> getQuads(IBlockState state, EnumFacing side, long rand)
         {

src/main/java/net/minecraftforge/client/model/animation/AnimationItemOverrideList.java

@@ -67,10 +67,10 @@ public final class AnimationItemOverrideList extends ItemOverrideList
     @Override
     public IBakedModel handleItemState(@Nonnull IBakedModel originalModel, @Nonnull ItemStack stack, @Nullable World world, @Nullable EntityLivingBase entity)
     {
-        if(stack.hasCapability(net.minecraftforge.common.model.animation.CapabilityAnimation.ANIMATION_CAPABILITY, null))
+        IAnimationStateMachine asm = stack.getCapability(CapabilityAnimation.ANIMATION_CAPABILITY, null);
+        if (asm != null)
         {
             // TODO: caching?
-            IAnimationStateMachine asm = stack.getCapability(CapabilityAnimation.ANIMATION_CAPABILITY, null);
             if(world == null && entity != null)
             {
                 world = entity.world;

src/main/java/net/minecraftforge/client/model/animation/AnimationModelBase.java

@@ -44,6 +44,7 @@ import net.minecraftforge.common.animation.IEventHandler;
 import net.minecraftforge.common.model.IModelState;
 import net.minecraftforge.common.model.animation.CapabilityAnimation;
 
+import net.minecraftforge.common.model.animation.IAnimationStateMachine;
 import org.apache.commons.lang3.tuple.Pair;
 import org.lwjgl.opengl.GL11;
 
@@ -67,12 +68,12 @@ public class AnimationModelBase<T extends Entity> extends ModelBase implements I
     @Override
     public void render(Entity entity, float limbSwing, float limbSwingSpeed, float timeAlive, float yawHead, float rotationPitch, float scale)
     {
-        if(!(entity.hasCapability(CapabilityAnimation.ANIMATION_CAPABILITY, null)))
+        IAnimationStateMachine capability = entity.getCapability(CapabilityAnimation.ANIMATION_CAPABILITY, null);
+        if (capability == null)
         {
             return;
         }
-
-        Pair<IModelState, Iterable<Event>> pair = entity.getCapability(CapabilityAnimation.ANIMATION_CAPABILITY, null).apply(timeAlive / 20);
+        Pair<IModelState, Iterable<Event>> pair = capability.apply(timeAlive / 20);
         handleEvents((T)entity, timeAlive / 20, pair.getRight());
         IModel model = ModelLoaderRegistry.getModelOrMissing(modelLocation);
         IBakedModel bakedModel = model.bake(pair.getLeft(), DefaultVertexFormats.ITEM, ModelLoader.defaultTextureGetter());

src/main/java/net/minecraftforge/client/model/animation/AnimationTESR.java

@@ -32,11 +32,14 @@ import net.minecraftforge.common.animation.Event;
 import net.minecraftforge.common.animation.IEventHandler;
 import net.minecraftforge.common.model.IModelState;
 import net.minecraftforge.common.model.animation.CapabilityAnimation;
+import net.minecraftforge.common.model.animation.IAnimationStateMachine;
 import net.minecraftforge.common.property.IExtendedBlockState;
 import net.minecraftforge.common.property.Properties;
 
 import org.apache.commons.lang3.tuple.Pair;
 
+import javax.annotation.Nonnull;
+
 /**
  * Generic TileEntitySpecialRenderer that works with the Forge model system and animations.
  */
@@ -44,7 +47,7 @@ public class AnimationTESR<T extends TileEntity> extends FastTESR<T> implements
 {
     protected static BlockRendererDispatcher blockRenderer;
 
-    public void renderTileEntityFast(T te, double x, double y, double z, float partialTick, int breakStage, VertexBuffer renderer)
+    public void renderTileEntityFast(@Nonnull T te, double x, double y, double z, float partialTick, int breakStage, @Nonnull VertexBuffer renderer)
     {
         if(!te.hasCapability(CapabilityAnimation.ANIMATION_CAPABILITY, null))
         {
@@ -64,16 +67,20 @@ public class AnimationTESR<T extends TileEntity> extends FastTESR<T> implements
             if(exState.getUnlistedNames().contains(Properties.AnimationProperty))
             {
                 float time = Animation.getWorldTime(getWorld(), partialTick);
-                Pair<IModelState, Iterable<Event>> pair = te.getCapability(CapabilityAnimation.ANIMATION_CAPABILITY, null).apply(time);
-                handleEvents(te, time, pair.getRight());
+                IAnimationStateMachine capability = te.getCapability(CapabilityAnimation.ANIMATION_CAPABILITY, null);
+                if (capability != null)
+                {
+                    Pair<IModelState, Iterable<Event>> pair = capability.apply(time);
+                    handleEvents(te, time, pair.getRight());
 
-                // TODO: caching?
-                IBakedModel model = blockRenderer.getBlockModelShapes().getModelForState(exState.getClean());
-                exState = exState.withProperty(Properties.AnimationProperty, pair.getLeft());
+                    // TODO: caching?
+                    IBakedModel model = blockRenderer.getBlockModelShapes().getModelForState(exState.getClean());
+                    exState = exState.withProperty(Properties.AnimationProperty, pair.getLeft());
 
-                renderer.setTranslation(x - pos.getX(), y - pos.getY(), z - pos.getZ());
+                    renderer.setTranslation(x - pos.getX(), y - pos.getY(), z - pos.getZ());
 
-                blockRenderer.getBlockModelRenderer().renderModel(world, model, exState, pos, renderer, false);
+                    blockRenderer.getBlockModelRenderer().renderModel(world, model, exState, pos, renderer, false);
+                }
             }
         }
     }

src/main/java/net/minecraftforge/client/model/animation/FastTESR.java

@@ -31,10 +31,12 @@ import net.minecraft.client.renderer.tileentity.TileEntitySpecialRenderer;
 import net.minecraft.client.renderer.vertex.DefaultVertexFormats;
 import net.minecraft.tileentity.TileEntity;
 
+import javax.annotation.Nonnull;
+
 public abstract class FastTESR<T extends TileEntity> extends TileEntitySpecialRenderer<T>
 {
     @Override
-    public final void renderTileEntityAt(T te, double x, double y, double z, float partialTicks, int destroyStage)
+    public final void renderTileEntityAt(@Nonnull T te, double x, double y, double z, float partialTicks, int destroyStage)
     {
         Tessellator tessellator = Tessellator.getInstance();
         VertexBuffer VertexBuffer = tessellator.getBuffer();
@@ -64,5 +66,5 @@ public abstract class FastTESR<T extends TileEntity> extends TileEntitySpecialRe
     }
 
     @Override
-    public abstract void renderTileEntityFast(T te, double x, double y, double z, float partialTicks, int destroyStage, VertexBuffer VertexBuffer);
+    public abstract void renderTileEntityFast(@Nonnull T te, double x, double y, double z, float partialTicks, int destroyStage, @Nonnull VertexBuffer VertexBuffer);
 }

src/main/java/net/minecraftforge/client/model/animation/ModelBlockAnimation.java

@@ -29,6 +29,7 @@ import java.util.Map;
 import java.util.NoSuchElementException;
 import java.util.TreeMap;
 
+import javax.annotation.Nullable;
 import javax.vecmath.AxisAngle4f;
 import javax.vecmath.Matrix4f;
 import javax.vecmath.Quat4f;
@@ -515,6 +516,7 @@ public class ModelBlockAnimation
         }
     }
 
+    @Nullable
     public TRSRTransformation getPartTransform(IModelState state, BlockPart part, int i)
     {
         ImmutableCollection<MBJointWeight> infos = getJoint(i);

src/main/java/net/minecraftforge/client/model/b3d/B3DLoader.java

@@ -30,6 +30,7 @@ import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.TimeUnit;
 
+import javax.annotation.Nullable;
 import javax.vecmath.Matrix4f;
 import javax.vecmath.Vector3f;
 
@@ -168,6 +169,7 @@ public enum B3DLoader implements ICustomModelLoader
         private final int frame;
         private final int nextFrame;
         private final float progress;
+        @Nullable
         private final IModelState parent;
 
         public B3DState(Animation animation, int frame)
@@ -185,7 +187,7 @@ public enum B3DLoader implements ICustomModelLoader
             this(animation, frame, nextFrame, progress, null);
         }
 
-        public B3DState(Animation animation, int frame, int nextFrame, float progress, IModelState parent)
+        public B3DState(Animation animation, int frame, int nextFrame, float progress, @Nullable IModelState parent)
         {
             this.animation = animation;
             this.frame = frame;
@@ -194,7 +196,8 @@ public enum B3DLoader implements ICustomModelLoader
             this.parent = getParent(parent);
         }
 
-        private IModelState getParent(IModelState parent)
+        @Nullable
+        private IModelState getParent(@Nullable IModelState parent)
         {
             if (parent == null) return null;
             else if (parent instanceof B3DState) return ((B3DState)parent).parent;
@@ -221,6 +224,7 @@ public enum B3DLoader implements ICustomModelLoader
             return progress;
         }
 
+        @Nullable
         public IModelState getParent()
         {
             return parent;

src/main/java/net/minecraftforge/client/model/obj/OBJModel.java

@@ -33,6 +33,7 @@ import java.util.Map;
 import java.util.Set;
 import java.util.regex.Pattern;
 
+import javax.annotation.Nullable;
 import javax.vecmath.Matrix3f;
 import javax.vecmath.Matrix4f;
 import javax.vecmath.Vector2f;
@@ -1068,7 +1069,7 @@ public class OBJModel implements IRetexturableModel, IModelCustomData
 //        public float[] minUVBounds = new float[] {0.0f, 0.0f};
 //        public float[] maxUVBounds = new float[] {1.0f, 1.0f};
 
-        public Group(String name, LinkedHashSet<Face> faces)
+        public Group(String name, @Nullable LinkedHashSet<Face> faces)
         {
             this.name = name != null ? name : DEFAULT_NAME;
             this.faces = faces == null ? new LinkedHashSet<Face>() : faces;
@@ -1129,6 +1130,7 @@ public class OBJModel implements IRetexturableModel, IModelCustomData
             for (String s : visibleGroups) this.visibilityMap.put(s, visibility);
         }
 
+        @Nullable
         public IModelState getParent(IModelState parent)
         {
             if (parent == null) return null;

src/main/java/net/minecraftforge/client/settings/KeyBindingMap.java

@@ -22,6 +22,7 @@ package net.minecraftforge.client.settings;
 import net.minecraft.client.settings.KeyBinding;
 import net.minecraft.util.IntHashMap;
 
+import javax.annotation.Nullable;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.EnumMap;
@@ -38,6 +39,7 @@ public class KeyBindingMap
         }
     }
 
+    @Nullable
     public KeyBinding lookupActive(int keyCode)
     {
         KeyModifier activeModifier = KeyModifier.getActiveModifier();
@@ -52,6 +54,7 @@ public class KeyBindingMap
         return getBinding(keyCode, KeyModifier.NONE);
     }
 
+    @Nullable
     private KeyBinding getBinding(int keyCode, KeyModifier keyModifier)
     {
         Collection<KeyBinding> bindings = map.get(keyModifier).lookup(keyCode);

src/main/java/net/minecraftforge/common/AchievementPage.java

@@ -32,6 +32,8 @@ import java.util.Set;
 
 import net.minecraft.stats.Achievement;
 
+import javax.annotation.Nullable;
+
 public class AchievementPage
 {
     private String name;
@@ -83,6 +85,7 @@ public class AchievementPage
      * @param name The page's name.
      * @return the achievement page with the given name or null if no such page
      */
+    @Nullable
     public static AchievementPage getAchievementPage(String name)
     {
         for (AchievementPage page : achievementPages)

src/main/java/net/minecraftforge/common/BiomeManager.java

@@ -33,6 +33,8 @@ import net.minecraft.world.biome.BiomeProvider;
 import net.minecraft.world.gen.structure.MapGenVillage;
 import net.minecraftforge.common.util.EnumHelper;
 
+import javax.annotation.Nullable;
+
 public class BiomeManager
 {
     private static TrackedList<BiomeEntry>[] biomes = setupBiomes();
@@ -154,6 +156,7 @@ public class BiomeManager
         }
     }
 
+    @Nullable
     public static ImmutableList<BiomeEntry> getBiomes(BiomeType type)
     {
         int idx = type.ordinal();

src/main/java/net/minecraftforge/common/DimensionManager.java

@@ -52,6 +52,8 @@ import net.minecraftforge.event.world.WorldEvent;
 import net.minecraftforge.fml.common.FMLCommonHandler;
 import net.minecraftforge.fml.common.FMLLog;
 
+import javax.annotation.Nullable;
+
 public class DimensionManager
 {
     private static Hashtable<Integer, WorldServer> worlds = new Hashtable<Integer, WorldServer>();
@@ -170,7 +172,7 @@ public class DimensionManager
         return worlds.keySet().toArray(new Integer[worlds.size()]); //Only loaded dims, since usually used to cycle through loaded worlds
     }
 
-    public static void setWorld(int id, WorldServer world, MinecraftServer server)
+    public static void setWorld(int id, @Nullable WorldServer world, MinecraftServer server)
     {
         if (world != null)
         {
@@ -357,7 +359,7 @@ public class DimensionManager
         return dimMap;
     }
 
-    public static void loadDimensionDataMap(NBTTagCompound compoundTag)
+    public static void loadDimensionDataMap(@Nullable NBTTagCompound compoundTag)
     {
         dimensionMap.clear();
         if (compoundTag == null)
@@ -387,6 +389,7 @@ public class DimensionManager
      * Return the current root directory for the world save. Accesses getSaveHandler from the overworld
      * @return the root directory of the save
      */
+    @Nullable
     public static File getCurrentSaveRootDirectory()
     {
         if (DimensionManager.getWorld(0) != null)

src/main/java/net/minecraftforge/common/ForgeChunkManager.java

@@ -139,7 +139,7 @@ public class ForgeChunkManager
             @Override
             public Chunk apply(@Nullable ChunkPos input)
             {
-                return world.getChunkFromChunkCoords(input.chunkXPos, input.chunkZPos);
+                return input == null ? null : world.getChunkFromChunkCoords(input.chunkXPos, input.chunkZPos);
             }
         }));
         world.theProfiler.endStartSection("regularChunkLoading");
@@ -687,6 +687,7 @@ public class ForgeChunkManager
         return playerTicketLength - playerTickets.get(username).size();
     }
 
+    @Nullable
     public static Ticket requestPlayerTicket(Object mod, String player, World world, Type type)
     {
         ModContainer mc = getContainer(mod);
@@ -713,6 +714,7 @@ public class ForgeChunkManager
      * @param type The type of ticket
      * @return A ticket with which to register chunks for loading, or null if no further tickets are available
      */
+    @Nullable
     public static Ticket requestTicket(Object mod, World world, Type type)
     {
         ModContainer container = getContainer(mod);
@@ -966,6 +968,7 @@ public class ForgeChunkManager
         }
     }
 
+    @Nullable
     public static Chunk fetchDormantChunk(long coords, World world)
     {
         Cache<Long, Chunk> cache = dormantChunkCache.get(world);
@@ -1110,6 +1113,7 @@ public class ForgeChunkManager
         return list;
     }
 
+    @Nullable
     public static ConfigCategory getConfigFor(Object mod)
     {
         ModContainer container = getContainer(mod);

src/main/java/net/minecraftforge/common/ForgeHooks.java

@@ -552,7 +552,7 @@ public class ForgeHooks
         return (MinecraftForge.EVENT_BUS.post(event) ? null : new float[]{event.getDistance(), event.getDamageMultiplier()});
     }
 
-    public static int getLootingLevel(Entity target, Entity killer, DamageSource cause)
+    public static int getLootingLevel(Entity target, @Nullable Entity killer, DamageSource cause)
     {
         int looting = 0;
         if (killer instanceof EntityLivingBase)
@@ -619,6 +619,7 @@ public class ForgeHooks
         MinecraftForge.EVENT_BUS.post(new LivingJumpEvent(entity));
     }
 
+    @Nullable
     public static EntityItem onPlayerTossEvent(@Nonnull EntityPlayer player, @Nonnull ItemStack item, boolean includeName)
     {
         player.captureDrops = true;
@@ -649,6 +650,7 @@ public class ForgeHooks
         return world.getBlockState(pos).getBlock().getEnchantPowerBonus(world, pos);
     }
 
+    @Nullable
     public static ITextComponent onServerChatEvent(NetHandlerPlayServer net, String raw, ITextComponent comp)
     {
         ServerChatEvent event = new ServerChatEvent(net.playerEntity, raw, comp);
@@ -793,7 +795,7 @@ public class ForgeHooks
         return event.isCanceled() ? -1 : event.getExpToDrop();
     }
 
-    public static EnumActionResult onPlaceItemIntoWorld(@Nonnull  ItemStack itemstack, EntityPlayer player, World world, BlockPos pos, EnumFacing side, float hitX, float hitY, float hitZ, EnumHand hand)
+    public static EnumActionResult onPlaceItemIntoWorld(@Nonnull ItemStack itemstack, @Nonnull EntityPlayer player, @Nonnull World world, @Nonnull BlockPos pos, @Nonnull EnumFacing side, float hitX, float hitY, float hitZ, @Nonnull EnumHand hand)
     {
         // handle all placement events here
         int meta = itemstack.getItemDamage();
@@ -896,7 +898,7 @@ public class ForgeHooks
         return false;
     }
 
-    public static float onAnvilRepair(EntityPlayer player, ItemStack output, ItemStack left, ItemStack right)
+    public static float onAnvilRepair(EntityPlayer player, @Nonnull ItemStack output, @Nonnull ItemStack left, @Nonnull ItemStack right)
     {
         AnvilRepairEvent e = new AnvilRepairEvent(player, left, right, output);
         MinecraftForge.EVENT_BUS.post(e);
@@ -1009,6 +1011,7 @@ public class ForgeHooks
         return !event.isCanceled();
     }
 
+    @Nullable
     public static RayTraceResult rayTraceEyes(EntityLivingBase entity, double length)
     {
         Vec3d startPos = new Vec3d(entity.posX, entity.posY + entity.getEyeHeight(), entity.posZ);
@@ -1016,6 +1019,7 @@ public class ForgeHooks
         return entity.world.rayTraceBlocks(startPos, endPos);
     }
 
+    @Nullable
     public static Vec3d rayTraceEyeHitVec(EntityLivingBase entity, double length)
     {
         RayTraceResult git = rayTraceEyes(entity, length);
@@ -1085,6 +1089,8 @@ public class ForgeHooks
 
         return ctx;
     }
+
+    @Nullable
     public static LootTable loadLootTable(Gson gson, ResourceLocation name, String data, boolean custom)
     {
         Deque<LootTableContext> que = lootContext.get();
@@ -1140,7 +1146,7 @@ public class ForgeHooks
 
         public String validateEntryName(@Nullable String name)
         {
-            if (!this.entryNames.contains(name))
+            if (name != null && !this.entryNames.contains(name))
             {
                 this.entryNames.add(name);
                 return name;

src/main/java/net/minecraftforge/common/ForgeModContainer.java

@@ -94,6 +94,8 @@ import net.minecraftforge.fml.common.eventhandler.SubscribeEvent;
 import net.minecraftforge.fml.common.gameevent.PlayerEvent;
 import net.minecraftforge.fml.common.network.NetworkRegistry;
 
+import javax.annotation.Nullable;
+
 public class ForgeModContainer extends DummyModContainer implements WorldAccessContainer
 {
     public static final String VERSION_CHECK_CAT = "version_checking";
@@ -541,6 +543,7 @@ public class ForgeModContainer extends DummyModContainer implements WorldAccessC
 
 
     @Override
+    @Nullable
     public Certificate getSigningCertificate()
     {
         Certificate[] certificates = getClass().getProtectionDomain().getCodeSource().getCertificates();

src/main/java/net/minecraftforge/common/ForgeVersion.java

@@ -47,6 +47,8 @@ import net.minecraftforge.fml.common.Loader;
 import net.minecraftforge.fml.common.ModContainer;
 import net.minecraftforge.fml.common.versioning.ComparableVersion;
 
+import javax.annotation.Nullable;
+
 public class ForgeVersion
 {
     // This is Forge's Mod Id, used for the ForgeModContainer and resource locations
@@ -93,6 +95,7 @@ public class ForgeVersion
         return getResult(ForgeModContainer.getInstance()).status;
     }
 
+    @Nullable
     public static String getTarget()
     {
         CheckResult res = getResult(ForgeModContainer.getInstance());
@@ -159,15 +162,17 @@ public class ForgeVersion
     public static class CheckResult
     {
         public final Status status;
+        @Nullable
         public final ComparableVersion target;
         public final Map<ComparableVersion, String> changes;
+        @Nullable
         public final String url;
 
-        private CheckResult(Status status, ComparableVersion target, Map<ComparableVersion, String> changes, String url)
+        private CheckResult(Status status, @Nullable ComparableVersion target, @Nullable Map<ComparableVersion, String> changes, @Nullable String url)
         {
             this.status = status;
             this.target = target;
-            this.changes = changes == null ? null : Collections.unmodifiableMap(changes);
+            this.changes = changes == null ? Collections.<ComparableVersion, String>emptyMap() : Collections.unmodifiableMap(changes);
             this.url = url;
         }
     }

src/main/java/net/minecraftforge/common/animation/TimeValues.java

@@ -35,6 +35,8 @@ import com.google.gson.stream.JsonReader;
 import com.google.gson.stream.JsonToken;
 import com.google.gson.stream.JsonWriter;
 
+import javax.annotation.Nullable;
+
 /**
  * Various implementations of ITimeValue.
  */
@@ -291,12 +293,13 @@ public final class TimeValues
 
         private final ThreadLocal<Function<String, ITimeValue>> valueResolver = new ThreadLocal<Function<String, ITimeValue>>();
 
-        public void setValueResolver(Function<String, ITimeValue> valueResolver)
+        public void setValueResolver(@Nullable Function<String, ITimeValue> valueResolver)
         {
             this.valueResolver.set(valueResolver);
         }
 
         @SuppressWarnings("unchecked")
+        @Nullable
         public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> type)
         {
             if(type.getRawType() != ITimeValue.class)

src/main/java/net/minecraftforge/common/brewing/AbstractBrewingRecipe.java

@@ -24,8 +24,9 @@ import net.minecraftforge.oredict.OreDictionary;
 
 import javax.annotation.Nonnull;
 
-public abstract class AbstractBrewingRecipe<T> implements IBrewingRecipe {
-
+public abstract class AbstractBrewingRecipe<T> implements IBrewingRecipe
+{
+    @Nonnull
     private final ItemStack input;
     private final T ingredient;
     private final ItemStack output;

src/main/java/net/minecraftforge/common/brewing/IBrewingRecipe.java

@@ -30,18 +30,19 @@ public interface IBrewingRecipe {
      * being the item that goes in one of the three bottom slots of the brewing
      * stand (e.g: water bottle)
      */
-    public boolean isInput(@Nonnull ItemStack input);
+    boolean isInput(@Nonnull ItemStack input);
 
     /**
      * Returns true if the passed ItemStack is an ingredient for this recipe.
      * "Ingredient" being the item that goes in the top slot of the brewing
      * stand (e.g: nether wart)
      */
-    public boolean isIngredient(@Nonnull ItemStack ingredient);
+    boolean isIngredient(@Nonnull ItemStack ingredient);
 
     /**
      * Returns the output when the passed input is brewed with the passed
-     * ingredient. Null if invalid input or ingredient.
+     * ingredient. Empty if invalid input or ingredient.
      */
-    public ItemStack getOutput(@Nonnull ItemStack input, @Nonnull ItemStack ingredient);
+    @Nonnull
+    ItemStack getOutput(@Nonnull ItemStack input, @Nonnull ItemStack ingredient);
 }

src/main/java/net/minecraftforge/common/brewing/VanillaBrewingRecipe.java

@@ -58,6 +58,7 @@ public class VanillaBrewingRecipe implements IBrewingRecipe {
      * or if the new potion is a splash potion when the old one wasn't.
      */
     @Override
+    @Nonnull
     public ItemStack getOutput(@Nonnull ItemStack input, @Nonnull ItemStack ingredient)
     {
         if (!input.isEmpty() && !ingredient.isEmpty() && isIngredient(ingredient))

src/main/java/net/minecraftforge/common/capabilities/Capability.java

@@ -26,6 +26,8 @@ import com.google.common.base.Throwables;
 import net.minecraft.nbt.NBTBase;
 import net.minecraft.util.EnumFacing;
 
+import javax.annotation.Nullable;
+
 /**
  * This is the core holder object Capabilities.
  * Each capability will have ONE instance of this class,
@@ -55,6 +57,7 @@ public class Capability<T>
          * @param side The side of the object the instance is associated with.
          * @return a NBT holding the data. Null if no data needs to be stored.
          */
+        @Nullable
         NBTBase writeNBT(Capability<T> capability, T instance, EnumFacing side);
 
         /**
@@ -103,6 +106,7 @@ public class Capability<T>
      * Quick access to the IStorage's writeNBT. 
      * See {@link IStorage#writeNBT(Capability, Object, EnumFacing)} for documentation.
      */
+    @Nullable
     public NBTBase writeNBT(T instance, EnumFacing side)
     {
     	return storage.writeNBT(this, instance, side);
@@ -117,6 +121,7 @@ public class Capability<T>
      *
      * @return A NEW instance of the default implementation.
      */
+    @Nullable
     public T getDefaultInstance()
     {
         try

src/main/java/net/minecraftforge/common/capabilities/CapabilityDispatcher.java

@@ -54,7 +54,7 @@ public final class CapabilityDispatcher implements INBTSerializable<NBTTagCompou
     }
 
     @SuppressWarnings("unchecked")
-    public CapabilityDispatcher(Map<ResourceLocation, ICapabilityProvider> list, ICapabilityProvider parent)
+    public CapabilityDispatcher(Map<ResourceLocation, ICapabilityProvider> list, @Nullable ICapabilityProvider parent)
     {
         List<ICapabilityProvider> lstCaps = Lists.newArrayList();
         List<INBTSerializable<NBTBase>> lstWriters = Lists.newArrayList();

src/main/java/net/minecraftforge/common/capabilities/CapabilityManager.java

@@ -39,6 +39,8 @@ import net.minecraftforge.common.util.EnumHelper;
 import net.minecraftforge.fml.common.FMLLog;
 import net.minecraftforge.fml.common.discovery.ASMDataTable;
 
+import javax.annotation.Nullable;
+
 public enum CapabilityManager
 {
     INSTANCE;
@@ -63,11 +65,10 @@ public enum CapabilityManager
                 try {
                     return implementation.newInstance();
                 } catch (InstantiationException e) {
-                    Throwables.propagate(e);
+                    throw Throwables.propagate(e);
                 } catch (IllegalAccessException e) {
-                    Throwables.propagate(e);
+                    throw Throwables.propagate(e);
                 }
-                return null;
             }
         });
     }
@@ -115,6 +116,7 @@ public enum CapabilityManager
             if (type == null)
             {
                 FMLLog.log(Level.WARN, "Unable to inject capability at %s.%s (Invalid Annotation)", targetClass, targetName);
+                continue;
             }
             final String capabilityName = type.getInternalName().replace('/', '.').intern();
 

src/main/java/net/minecraftforge/common/model/TRSRTransformation.java

@@ -21,6 +21,7 @@ package net.minecraftforge.common.model;
 
 import java.util.EnumMap;
 
+import javax.annotation.Nullable;
 import javax.vecmath.AxisAngle4f;
 import javax.vecmath.Matrix3f;
 import javax.vecmath.Matrix4f;
@@ -78,7 +79,7 @@ public final class TRSRTransformation implements IModelState, ITransformation
         }
     }
 
-    public TRSRTransformation(Vector3f translation, Quat4f leftRot, Vector3f scale, Quat4f rightRot)
+    public TRSRTransformation(@Nullable Vector3f translation, @Nullable Quat4f leftRot, @Nullable Vector3f scale, @Nullable Quat4f rightRot)
     {
         this.matrix = mul(translation, leftRot, scale, rightRot);
         this.translation = translation != null ? translation : new Vector3f();
@@ -260,7 +261,7 @@ public final class TRSRTransformation implements IModelState, ITransformation
         );
     }
 
-    public static Matrix4f mul(Vector3f translation, Quat4f leftRot, Vector3f scale, Quat4f rightRot)
+    public static Matrix4f mul(@Nullable Vector3f translation, @Nullable Quat4f leftRot, @Nullable Vector3f scale, @Nullable Quat4f rightRot)
     {
         Matrix4f res = new Matrix4f(), t = new Matrix4f();
         res.setIdentity();

src/main/java/net/minecraftforge/common/model/animation/AnimationStateMachine.java

@@ -57,6 +57,8 @@ import com.google.common.cache.CacheLoader;
 import com.google.common.cache.LoadingCache;
 import com.google.gson.annotations.SerializedName;
 
+import javax.annotation.Nullable;
+
 public final class AnimationStateMachine implements IAnimationStateMachine
 {
     private final ImmutableMap<String, ITimeValue> parameters;
@@ -310,6 +312,7 @@ public final class AnimationStateMachine implements IAnimationStateMachine
         INSTANCE;
 
         @SuppressWarnings("unchecked")
+        @Nullable
         public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> type)
         {
             if(type.getRawType() != ImmutableMultimap.class || !(type.getType() instanceof ParameterizedType))

src/main/java/net/minecraftforge/common/model/animation/Clips.java

@@ -53,6 +53,8 @@ import com.google.gson.reflect.TypeToken;
 import com.google.gson.stream.JsonReader;
 import com.google.gson.stream.JsonWriter;
 
+import javax.annotation.Nullable;
+
 /**
  * Various implementations of IClip, and utility methods.
  */
@@ -426,12 +428,13 @@ public final class Clips
 
         private final ThreadLocal<Function<String, IClip>> clipResolver = new ThreadLocal<Function<String, IClip>>();
 
-        public void setClipResolver(Function<String, IClip> clipResolver)
+        public void setClipResolver(@Nullable Function<String, IClip> clipResolver)
         {
             this.clipResolver.set(clipResolver);
         }
 
         @SuppressWarnings("unchecked")
+        @Nullable
         public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> type)
         {
             if(type.getRawType() != IClip.class)

src/main/java/net/minecraftforge/common/property/ExtendedBlockState.java

@@ -37,6 +37,9 @@ import com.google.common.collect.ImmutableTable;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.Maps;
 
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+
 public class ExtendedBlockState extends BlockStateContainer
 {
     private final ImmutableSet<IUnlistedProperty<?>> unlistedProperties;
@@ -68,7 +71,8 @@ public class ExtendedBlockState extends BlockStateContainer
     }
 
     @Override
-    protected StateImplementation createState(Block block, ImmutableMap<IProperty<?>, Comparable<?>> properties, ImmutableMap<IUnlistedProperty<?>, Optional<?>> unlistedProperties)
+    @Nonnull
+    protected StateImplementation createState(@Nonnull Block block, @Nonnull  ImmutableMap<IProperty<?>, Comparable<?>> properties, @Nullable ImmutableMap<IUnlistedProperty<?>, Optional<?>> unlistedProperties)
     {
         if (unlistedProperties == null || unlistedProperties.isEmpty()) return super.createState(block, properties, unlistedProperties);
         return new ExtendedStateImplementation(block, properties, unlistedProperties, null);
@@ -79,7 +83,7 @@ public class ExtendedBlockState extends BlockStateContainer
         private final ImmutableMap<IUnlistedProperty<?>, Optional<?>> unlistedProperties;
         private Map<Map<IProperty<?>, Comparable<?>>, BlockStateContainer.StateImplementation> normalMap;
 
-        protected ExtendedStateImplementation(Block block, ImmutableMap<IProperty<?>, Comparable<?>> properties, ImmutableMap<IUnlistedProperty<?>, Optional<?>> unlistedProperties, ImmutableTable<IProperty<?>, Comparable<?>, IBlockState> table)
+        protected ExtendedStateImplementation(Block block, ImmutableMap<IProperty<?>, Comparable<?>> properties, ImmutableMap<IUnlistedProperty<?>, Optional<?>> unlistedProperties, @Nullable ImmutableTable<IProperty<?>, Comparable<?>, IBlockState> table)
         {
             super(block, properties);
             this.unlistedProperties = unlistedProperties;
@@ -87,7 +91,8 @@ public class ExtendedBlockState extends BlockStateContainer
         }
 
         @Override
-        public <T extends Comparable<T>, V extends T> IBlockState withProperty(IProperty<T> property, V value)
+        @Nonnull
+        public <T extends Comparable<T>, V extends T> IBlockState withProperty(@Nonnull IProperty<T> property, @Nonnull V value)
         {
             if (!this.getProperties().containsKey(property))
             {

src/main/java/net/minecraftforge/common/util/BlockSnapshot.java

@@ -30,6 +30,8 @@ import net.minecraft.world.World;
 import net.minecraftforge.common.DimensionManager;
 import net.minecraftforge.fml.common.registry.ForgeRegistries;
 
+import javax.annotation.Nullable;
+
 /**
  * Represents a captured snapshot of a block which will not change
  * automatically.
@@ -46,6 +48,7 @@ public class BlockSnapshot implements Serializable
     private final int dimId;
     private transient IBlockState replacedBlock;
     private int flag;
+    @Nullable
     private final NBTTagCompound nbt;
     private transient World world;
     private final ResourceLocation registryName;
@@ -73,7 +76,7 @@ public class BlockSnapshot implements Serializable
         }
     }
 
-    public BlockSnapshot(World world, BlockPos pos, IBlockState state, NBTTagCompound nbt)
+    public BlockSnapshot(World world, BlockPos pos, IBlockState state, @Nullable NBTTagCompound nbt)
     {
         this.setWorld(world);
         this.dimId = world.provider.getDimension();
@@ -98,7 +101,7 @@ public class BlockSnapshot implements Serializable
     /**
      * Raw constructor designed for serialization usages.
      */
-    public BlockSnapshot(int dimension, BlockPos pos, String modId, String blockName, int meta, int flag, NBTTagCompound nbt)
+    public BlockSnapshot(int dimension, BlockPos pos, String modId, String blockName, int meta, int flag, @Nullable NBTTagCompound nbt)
     {
         this.dimId = dimension;
         this.pos = pos.toImmutable();
@@ -322,6 +325,7 @@ public class BlockSnapshot implements Serializable
     public void setReplacedBlock(IBlockState replacedBlock) { this.replacedBlock = replacedBlock; }
     public int getFlag() { return flag; }
     public void setFlag(int flag) { this.flag = flag; }
+    @Nullable
     public NBTTagCompound getNbt() { return nbt; }
     public void setWorld(World world) { this.world = world; }
     public ResourceLocation getRegistryName() { return registryName; }

src/main/java/net/minecraftforge/common/util/EnumHelper.java

@@ -46,6 +46,8 @@ import net.minecraft.world.EnumSkyBlock;
 import net.minecraft.world.gen.structure.StructureStrongholdPieces.Stronghold.Door;
 import net.minecraftforge.classloading.FMLForgePlugin;
 
+import javax.annotation.Nullable;
+
 public class EnumHelper
 {
     private static Object reflectionFactory      = null;
@@ -73,54 +75,67 @@ public class EnumHelper
         {EnumRarity.class, TextFormatting.class, String.class}
     };
 
+    @Nullable
     public static EnumAction addAction(String name)
     {
         return addEnum(EnumAction.class, name);
     }
+    @Nullable
     public static ArmorMaterial addArmorMaterial(String name, String textureName, int durability, int[] reductionAmounts, int enchantability, SoundEvent soundOnEquip, float toughness)
     {
         return addEnum(ArmorMaterial.class, name, textureName, durability, reductionAmounts, enchantability, soundOnEquip, toughness);
     }
+    @Nullable
     public static EnumArt addArt(String name, String tile, int sizeX, int sizeY, int offsetX, int offsetY)
     {
         return addEnum(EnumArt.class, name, tile, sizeX, sizeY, offsetX, offsetY);
     }
+    @Nullable
     public static EnumCreatureAttribute addCreatureAttribute(String name)
     {
         return addEnum(EnumCreatureAttribute.class, name);
     }
+    @Nullable
     public static EnumCreatureType addCreatureType(String name, Class<?> typeClass, int maxNumber, Material material, boolean peaceful, boolean animal)
     {
         return addEnum(EnumCreatureType.class, name, typeClass, maxNumber, material, peaceful, animal);
     }
+    @Nullable
     public static Door addDoor(String name)
     {
         return addEnum(Door.class, name);
     }
+    @Nullable
     public static EnumEnchantmentType addEnchantmentType(String name, Predicate<Item> delegate)
     {
         return addEnum(EnumEnchantmentType.class, name, delegate);
     }
+    @Nullable
     public static Sensitivity addSensitivity(String name)
     {
         return addEnum(Sensitivity.class, name);
     }
+    @Nullable
     public static RayTraceResult.Type addMovingObjectType(String name)
     {
         return addEnum(RayTraceResult.Type.class, name);
     }
+    @Nullable
     public static EnumSkyBlock addSkyBlock(String name, int lightValue)
     {
         return addEnum(EnumSkyBlock.class, name, lightValue);
     }
+    @Nullable
     public static SleepResult addStatus(String name)
     {
         return addEnum(SleepResult.class, name);
     }
+    @Nullable
     public static ToolMaterial addToolMaterial(String name, int harvestLevel, int maxUses, float efficiency, float damage, int enchantability)
     {
         return addEnum(ToolMaterial.class, name, harvestLevel, maxUses, efficiency, damage, enchantability);
     }
+    @Nullable
     public static EnumRarity addRarity(String name, TextFormatting color, String displayName)
     {
         return addEnum(EnumRarity.class, name, color, displayName);
@@ -164,16 +179,20 @@ public class EnumHelper
         return newConstructorAccessor.invoke(reflectionFactory, enumClass.getDeclaredConstructor(parameterTypes));
     }
 
-    private static < T extends Enum<? >> T makeEnum(Class<T> enumClass, String value, int ordinal, Class<?>[] additionalTypes, Object[] additionalValues) throws Exception
+    private static < T extends Enum<? >> T makeEnum(Class<T> enumClass, @Nullable String value, int ordinal, Class<?>[] additionalTypes, @Nullable Object[] additionalValues) throws Exception
     {
-        Object[] params = new Object[additionalValues.length + 2];
+        int additionalParamsCount = additionalValues == null ? 0 : additionalValues.length;
+        Object[] params = new Object[additionalParamsCount + 2];
         params[0] = value;
         params[1] = ordinal;
-        System.arraycopy(additionalValues, 0, params, 2, additionalValues.length);
+        if (additionalValues != null)
+        {
+            System.arraycopy(additionalValues, 0, params, 2, additionalValues.length);
+        }
         return enumClass.cast(newInstance.invoke(getConstructorAccessor(enumClass, additionalTypes), new Object[] {params}));
     }
 
-    public static void setFailsafeFieldValue(Field field, Object target, Object value) throws Exception
+    public static void setFailsafeFieldValue(Field field, @Nullable Object target, @Nullable Object value) throws Exception
     {
         field.setAccessible(true);
         Field modifiersField = Field.class.getDeclaredField("modifiers");
@@ -202,12 +221,14 @@ public class EnumHelper
         blankField(enumClass, "enumConstants");
     }
 
+    @Nullable
     private static <T extends Enum<? >> T addEnum(Class<T> enumType, String enumName, Object... paramValues)
     {
         setup();
         return addEnum(commonTypes, enumType, enumName, paramValues);
     }
 
+    @Nullable
     protected static <T extends Enum<? >> T addEnum(Class<?>[][] map, Class<T> enumType, String enumName, Object... paramValues)
     {
         for (Class<?>[] lookup : map)
@@ -231,13 +252,15 @@ public class EnumHelper
         addEnum(true, enumType, null, paramTypes, (Object[])null);
     }
 
+    @Nullable
     public static <T extends Enum<? >> T addEnum(Class<T> enumType, String enumName, Class<?>[] paramTypes, Object... paramValues)
     {
         return addEnum(false, enumType, enumName, paramTypes, paramValues);
     }
 
     @SuppressWarnings({ "unchecked", "serial" })
-    private static <T extends Enum<? >> T addEnum(boolean test, final Class<T> enumType, String enumName, final Class<?>[] paramTypes, Object[] paramValues)
+    @Nullable
+    private static <T extends Enum<? >> T addEnum(boolean test, final Class<T> enumType, @Nullable String enumName, final Class<?>[] paramTypes, @Nullable Object[] paramValues)
     {
         if (!isSetup)
         {

src/main/java/net/minecraftforge/event/ForgeEventFactory.java

@@ -143,10 +143,10 @@ public class ForgeEventFactory
     @Deprecated
     public static PlaceEvent onPlayerBlockPlace(EntityPlayer player, BlockSnapshot blockSnapshot, EnumFacing direction)
     {
-        return onPlayerBlockPlace(player, blockSnapshot, direction, null);
+        return onPlayerBlockPlace(player, blockSnapshot, direction, EnumHand.MAIN_HAND);
     }
 
-    public static PlaceEvent onPlayerBlockPlace(EntityPlayer player, BlockSnapshot blockSnapshot, EnumFacing direction, @Nullable EnumHand hand)
+    public static PlaceEvent onPlayerBlockPlace(@Nonnull EntityPlayer player, @Nonnull BlockSnapshot blockSnapshot, @Nonnull EnumFacing direction, @Nonnull EnumHand hand)
     {
         IBlockState placedAgainst = blockSnapshot.getWorld().getBlockState(blockSnapshot.getPos().offset(direction.getOpposite()));
         PlaceEvent event = new PlaceEvent(blockSnapshot, placedAgainst, player, hand);
@@ -223,6 +223,7 @@ public class ForgeEventFactory
        return event.getDroppedExperience();
     }
 
+    @Nullable
     public static List<Biome.SpawnListEntry> getPotentialSpawns(WorldServer world, EnumCreatureType type, BlockPos pos, List<Biome.SpawnListEntry> oldList)
     {
         WorldEvent.PotentialSpawns event = new WorldEvent.PotentialSpawns(world, type, pos, oldList);
@@ -331,6 +332,7 @@ public class ForgeEventFactory
         MinecraftForge.EVENT_BUS.post(new PlayerEvent.LoadFromFile(player, dir, uuidString));
     }
 
+    @Nullable
     public static ITextComponent onClientChat(byte type, ITextComponent message)
     {
         ClientChatReceivedEvent event = new ClientChatReceivedEvent(type, message);
@@ -362,7 +364,8 @@ public class ForgeEventFactory
         return 0;
     }
 
-    public static ActionResult<ItemStack> onBucketUse(EntityPlayer player, World world, ItemStack stack, RayTraceResult target)
+    @Nullable
+    public static ActionResult<ItemStack> onBucketUse(@Nonnull EntityPlayer player, @Nonnull World world, @Nonnull ItemStack stack, @Nullable RayTraceResult target)
     {
         FillBucketEvent event = new FillBucketEvent(player, stack, world, target);
         if (MinecraftForge.EVENT_BUS.post(event)) return new ActionResult<ItemStack>(EnumActionResult.FAIL, stack);
@@ -543,27 +546,32 @@ public class ForgeEventFactory
         return MinecraftForge.EVENT_BUS.post(new RenderBlockOverlayEvent(player, renderPartialTicks, type, block, pos));
     }
 
+    @Nullable
     public static CapabilityDispatcher gatherCapabilities(TileEntity tileEntity)
     {
         return gatherCapabilities(new AttachCapabilitiesEvent.TileEntity(tileEntity), null);
     }
 
+    @Nullable
     public static CapabilityDispatcher gatherCapabilities(Entity entity)
     {
         return gatherCapabilities(new AttachCapabilitiesEvent.Entity(entity), null);
     }
 
+    @Nullable
     public static CapabilityDispatcher gatherCapabilities(Item item, ItemStack stack, ICapabilityProvider parent)
     {
         return gatherCapabilities(new AttachCapabilitiesEvent.Item(item, stack), parent);
     }
 
+    @Nullable
     public static CapabilityDispatcher gatherCapabilities(World world, ICapabilityProvider parent)
     {
         return gatherCapabilities(new AttachCapabilitiesEvent.World(world), parent);
     }
 
-    private static CapabilityDispatcher gatherCapabilities(AttachCapabilitiesEvent event, ICapabilityProvider parent)
+    @Nullable
+    private static CapabilityDispatcher gatherCapabilities(AttachCapabilitiesEvent<?> event, @Nullable ICapabilityProvider parent)
     {
         MinecraftForge.EVENT_BUS.post(event);
         return event.getCapabilities().size() > 0 || parent != null ? new CapabilityDispatcher(event.getCapabilities(), parent) : null;

src/main/java/net/minecraftforge/event/brewing/PotionBrewEvent.java

@@ -42,7 +42,7 @@ public class PotionBrewEvent extends Event
     @Nonnull
     public ItemStack getItem(int index)
     {
-        if (index >= stacks.size()) return ItemStack.EMPTY;
+        if (index < 0 || index >= stacks.size()) return ItemStack.EMPTY;
         return stacks.get(index);
     }
 

src/main/java/net/minecraftforge/event/enchanting/EnchantmentLevelSetEvent.java

@@ -24,6 +24,8 @@ import net.minecraft.util.math.BlockPos;
 import net.minecraft.world.World;
 import net.minecraftforge.fml.common.eventhandler.Event;
 
+import javax.annotation.Nonnull;
+
 /**
  * Fired when the enchantment level is set for each of the three potential enchantments in the enchanting table.
  * The {@link #level} is set to the vanilla value and can be modified by this event handler.
@@ -38,11 +40,12 @@ public class EnchantmentLevelSetEvent extends Event
     private final BlockPos pos;
     private final int enchantRow;
     private final int power;
+    @Nonnull
     private final ItemStack itemStack;
     private final int originalLevel;
     private int level;
 
-    public EnchantmentLevelSetEvent(World world, BlockPos pos, int enchantRow, int power, ItemStack itemStack, int level)
+    public EnchantmentLevelSetEvent(World world, BlockPos pos, int enchantRow, int power, @Nonnull ItemStack itemStack, int level)
     {
         this.world = world;
         this.pos = pos;
@@ -98,6 +101,7 @@ public class EnchantmentLevelSetEvent extends Event
      * 
      * @return the item being enchanted
      */
+    @Nonnull
     public ItemStack getItem()
     {
         return itemStack;

src/main/java/net/minecraftforge/event/entity/living/LivingEquipmentChangeEvent.java

@@ -25,6 +25,8 @@ import net.minecraft.item.ItemStack;
 import net.minecraftforge.common.MinecraftForge;
 import net.minecraftforge.fml.common.eventhandler.Cancelable;
 
+import javax.annotation.Nonnull;
+
 /**
  * {@link LivingEquipmentChangeEvent} is fired when the Equipment of a Entity changes. <br>
  * This event is fired whenever changes in Equipment are detected in {@link EntityLivingBase#onUpdate()}. <br>
@@ -47,7 +49,7 @@ public class LivingEquipmentChangeEvent extends LivingEvent
     private final ItemStack from;
     private final ItemStack to;
 
-    public LivingEquipmentChangeEvent(EntityLivingBase entity, EntityEquipmentSlot slot, ItemStack from, ItemStack to)
+    public LivingEquipmentChangeEvent(EntityLivingBase entity, EntityEquipmentSlot slot, @Nonnull ItemStack from, @Nonnull ItemStack to)
     {
         super(entity);
         this.slot = slot;
@@ -56,6 +58,8 @@ public class LivingEquipmentChangeEvent extends LivingEvent
     }
 
     public EntityEquipmentSlot getSlot() { return this.slot; }
+    @Nonnull
     public ItemStack getFrom() { return this.from; }
+    @Nonnull
     public ItemStack getTo() { return this.to; }
 }

src/main/java/net/minecraftforge/event/entity/player/AnvilRepairEvent.java

@@ -33,13 +33,15 @@ import javax.annotation.Nonnull;
  */
 public class AnvilRepairEvent extends PlayerEvent
 {
-
+    @Nonnull
     private final ItemStack left; // The left side of the input
+    @Nonnull
     private final ItemStack right; // The right side of the input
+    @Nonnull
     private final ItemStack output; // Set this to set the output stack
     private float breakChance; // Anvil's chance to break (reduced by 1 durability) when this is complete. Default is 12% (0.12f)
 
-    public AnvilRepairEvent(EntityPlayer player, @Nonnull ItemStack left, @Nonnull ItemStack right, ItemStack output)
+    public AnvilRepairEvent(EntityPlayer player, @Nonnull ItemStack left, @Nonnull ItemStack right, @Nonnull ItemStack output)
     {
         super(player);
         this.output = output;
@@ -53,18 +55,21 @@ public class AnvilRepairEvent extends PlayerEvent
      * @return the output slot
      */
     @Deprecated
+    @Nonnull
     public ItemStack getLeft() { return output; }
     /**
      * Deprecated in favour of {@link #getIngredientInput()}} - this is actually the first input slot of the anvil
      * @return the first input slot
      */
     @Deprecated
+    @Nonnull
     public ItemStack getRight() { return left; }
     /**
      * Deprecated in favour of {@link #getItemResult()} - this is actually the second input slot of the anvil
      * @return the second input slot
      */
     @Deprecated
+    @Nonnull
     public ItemStack getOutput() { return right; }
 
     /**

src/main/java/net/minecraftforge/event/entity/player/FillBucketEvent.java

@@ -27,6 +27,7 @@ import net.minecraft.util.math.RayTraceResult;
 import net.minecraft.world.World;
 
 import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
 
 /**
  * This event is fired when a player attempts to use a Empty bucket, it
@@ -44,11 +45,12 @@ public class FillBucketEvent extends PlayerEvent
 
     private final ItemStack current;
     private final World world;
+    @Nullable
     private final RayTraceResult target;
 
     private ItemStack result;
 
-    public FillBucketEvent(EntityPlayer player, @Nonnull ItemStack current, World world, RayTraceResult target)
+    public FillBucketEvent(EntityPlayer player, @Nonnull ItemStack current, World world, @Nullable RayTraceResult target)
     {
         super(player);
         this.current = current;
@@ -59,6 +61,7 @@ public class FillBucketEvent extends PlayerEvent
     @Nonnull
     public ItemStack getEmptyBucket() { return this.current; }
     public World getWorld(){ return this.world; }
+    @Nullable
     public RayTraceResult getTarget() { return this.target; }
     @Nonnull
     public ItemStack getFilledBucket() { return this.result; }

src/main/java/net/minecraftforge/event/entity/player/PlayerInteractEvent.java

@@ -47,9 +47,10 @@ public class PlayerInteractEvent extends PlayerEvent
 {
     private final EnumHand hand;
     private final BlockPos pos;
+    @Nullable
     private final EnumFacing face;
 
-    private PlayerInteractEvent(EntityPlayer player, EnumHand hand, BlockPos pos, EnumFacing face)
+    private PlayerInteractEvent(EntityPlayer player, EnumHand hand, BlockPos pos, @Nullable EnumFacing face)
     {
         super(Preconditions.checkNotNull(player, "Null player in PlayerInteractEvent!"));
         this.hand = Preconditions.checkNotNull(hand, "Null hand in PlayerInteractEvent!");

src/main/java/net/minecraftforge/event/world/BlockEvent.java

@@ -40,6 +40,7 @@ import net.minecraftforge.fml.common.eventhandler.Event.Result;
 
 import com.google.common.collect.ImmutableList;
 
+import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 
 public class BlockEvent extends Event
@@ -171,7 +172,6 @@ public class BlockEvent extends Event
     public static class PlaceEvent extends BlockEvent
     {
         private final EntityPlayer player;
-        private final ItemStack itemInHand;
         private final BlockSnapshot blockSnapshot;
         private final IBlockState placedBlock;
         private final IBlockState placedAgainst;
@@ -180,30 +180,29 @@ public class BlockEvent extends Event
         @Deprecated
         public PlaceEvent(BlockSnapshot blockSnapshot, IBlockState placedAgainst, EntityPlayer player)
         {
-            this(blockSnapshot, placedAgainst, player, null);
+            this(blockSnapshot, placedAgainst, player, EnumHand.MAIN_HAND);
         }
 
-        public PlaceEvent(BlockSnapshot blockSnapshot, IBlockState placedAgainst, EntityPlayer player, @Nullable EnumHand hand) {
+        public PlaceEvent(@Nonnull BlockSnapshot blockSnapshot, @Nonnull IBlockState placedAgainst, @Nonnull EntityPlayer player, @Nonnull EnumHand hand) {
             super(blockSnapshot.getWorld(), blockSnapshot.getPos(), blockSnapshot.getCurrentBlock());
             this.player = player;
-            this.itemInHand = player.getHeldItem(hand != null ? hand : EnumHand.MAIN_HAND);
             this.blockSnapshot = blockSnapshot;
             this.placedBlock = blockSnapshot.getCurrentBlock();
             this.placedAgainst = placedAgainst;
             this.hand = hand;
             if (DEBUG)
             {
-                System.out.printf("Created PlaceEvent - [PlacedBlock: %s ][PlacedAgainst: %s ][ItemStack: %s ][Player: %s ][Hand: %s]\n", getPlacedBlock(), placedAgainst, getItemInHand(), player, hand);
+                System.out.printf("Created PlaceEvent - [PlacedBlock: %s ][PlacedAgainst: %s ][ItemStack: %s ][Player: %s ][Hand: %s]\n", getPlacedBlock(), placedAgainst, player.getHeldItem(hand), player, hand);
             }
         }
 
         public EntityPlayer getPlayer() { return player; }
-        @Nullable
-        public ItemStack getItemInHand() { return itemInHand; }
+        @Nonnull
+        @Deprecated
+        public ItemStack getItemInHand() { return player.getHeldItem(hand); }
         public BlockSnapshot getBlockSnapshot() { return blockSnapshot; }
         public IBlockState getPlacedBlock() { return placedBlock; }
         public IBlockState getPlacedAgainst() { return placedAgainst; }
-        @Nullable
         public EnumHand getHand() { return hand; }
     }
 
@@ -222,15 +221,15 @@ public class BlockEvent extends Event
         @Deprecated
         public MultiPlaceEvent(List<BlockSnapshot> blockSnapshots, IBlockState placedAgainst, EntityPlayer player)
         {
-            this(blockSnapshots, placedAgainst, player, null);
+            this(blockSnapshots, placedAgainst, player, EnumHand.MAIN_HAND);
         }
 
-        public MultiPlaceEvent(List<BlockSnapshot> blockSnapshots, IBlockState placedAgainst, EntityPlayer player, @Nullable EnumHand hand) {
+        public MultiPlaceEvent(@Nonnull List<BlockSnapshot> blockSnapshots, @Nonnull IBlockState placedAgainst, @Nonnull EntityPlayer player, @Nonnull EnumHand hand) {
             super(blockSnapshots.get(0), placedAgainst, player, hand);
             this.blockSnapshots = ImmutableList.copyOf(blockSnapshots);
             if (DEBUG)
             {
-                System.out.printf("Created MultiPlaceEvent - [PlacedAgainst: %s ][ItemInHand: %s ][Player: %s ]\n", placedAgainst, this.getItemInHand(), player);
+                System.out.printf("Created MultiPlaceEvent - [PlacedAgainst: %s ][ItemInHand: %s ][Player: %s ]\n", placedAgainst, player.getHeldItem(hand), player);
             }
         }
 

src/main/java/net/minecraftforge/fluids/BlockFluidClassic.java

@@ -30,6 +30,7 @@ import net.minecraft.world.World;
 import net.minecraftforge.event.ForgeEventFactory;
 
 import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
 
 /**
  * This is a fluid block implementation which emulates vanilla Minecraft fluid behavior.
@@ -373,6 +374,7 @@ public class BlockFluidClassic extends BlockFluidBase
     }
 
     @Override
+    @Nullable
     public FluidStack drain(World world, BlockPos pos, boolean doDrain)
     {
         if (!isSourceBlock(world, pos))

src/main/java/net/minecraftforge/fluids/FluidRegistry.java

@@ -49,6 +49,8 @@ import net.minecraftforge.fml.common.ModContainer;
 import net.minecraftforge.fml.common.eventhandler.Event;
 import net.minecraftforge.fml.common.registry.RegistryDelegate;
 
+import javax.annotation.Nullable;
+
 /**
  * Handles Fluid registrations. Fluids MUST be registered in order to function.
  */
@@ -219,6 +221,7 @@ public abstract class FluidRegistry
         return getFluidName(stack.getFluid());
     }
 
+    @Nullable
     public static FluidStack getFluidStack(String fluidName, int amount)
     {
         if (!fluids.containsKey(fluidName))
@@ -255,7 +258,9 @@ public abstract class FluidRegistry
     {
         if (Loader.instance().hasReachedState(LoaderState.PREINITIALIZATION))
         {
-            FMLLog.getLogger().log(Level.ERROR, "Trying to activate the universal filled bucket too late. Call it statically in your Mods class. Mod: {}", Loader.instance().activeModContainer().getName());
+            ModContainer modContainer = Loader.instance().activeModContainer();
+            String modContainerName = modContainer == null ? null : modContainer.getName();
+            FMLLog.getLogger().log(Level.ERROR, "Trying to activate the universal filled bucket too late. Call it statically in your Mods class. Mod: {}", modContainerName);
         }
         else
         {

src/main/java/net/minecraftforge/fluids/FluidStack.java

@@ -22,9 +22,12 @@ package net.minecraftforge.fluids;
 
 import net.minecraft.item.ItemStack;
 import net.minecraft.nbt.NBTTagCompound;
+import net.minecraftforge.common.util.Constants;
 import net.minecraftforge.fml.common.FMLLog;
 import net.minecraftforge.fml.common.registry.RegistryDelegate;
 
+import javax.annotation.Nullable;
+
 /**
  * ItemStack substitute for Fluids.
  *
@@ -74,15 +77,20 @@ public class FluidStack
      * This provides a safe method for retrieving a FluidStack - if the Fluid is invalid, the stack
      * will return as null.
      */
+    @Nullable
     public static FluidStack loadFluidStackFromNBT(NBTTagCompound nbt)
     {
         if (nbt == null)
         {
             return null;
         }
-        String fluidName = nbt.getString("FluidName");
+        if (!nbt.hasKey("FluidName", Constants.NBT.TAG_STRING))
+        {
+            return null;
+        }
 
-        if (fluidName == null || FluidRegistry.getFluid(fluidName) == null)
+        String fluidName = nbt.getString("FluidName");
+        if (FluidRegistry.getFluid(fluidName) == null)
         {
             return null;
         }
@@ -137,7 +145,7 @@ public class FluidStack
      *            The FluidStack for comparison
      * @return true if the Fluids (IDs and NBT Tags) are the same
      */
-    public boolean isFluidEqual(FluidStack other)
+    public boolean isFluidEqual(@Nullable FluidStack other)
     {
         return other != null && getFluid() == other.getFluid() && isFluidStackTagEqual(other);
     }
@@ -150,7 +158,7 @@ public class FluidStack
     /**
      * Determines if the NBT Tags are equal. Useful if the FluidIDs are known to be equal.
      */
-    public static boolean areFluidStackTagsEqual(FluidStack stack1, FluidStack stack2)
+    public static boolean areFluidStackTagsEqual(@Nullable FluidStack stack1, @Nullable FluidStack stack2)
     {
         return stack1 == null && stack2 == null ? true : stack1 == null || stack2 == null ? false : stack1.isFluidStackTagEqual(stack2);
     }
@@ -161,7 +169,7 @@ public class FluidStack
      * @param other
      * @return true if this FluidStack contains the other FluidStack (same fluid and >= amount)
      */
-    public boolean containsFluid(FluidStack other)
+    public boolean containsFluid(@Nullable FluidStack other)
     {
         return isFluidEqual(other) && amount >= other.amount;
     }

src/main/java/net/minecraftforge/fluids/FluidTank.java

@@ -237,6 +237,7 @@ public class FluidTank implements IFluidTank, IFluidHandler
      * Use this method to bypass the restrictions from {@link #canDrainFluidType(FluidStack)}
      * Meant for use by the owner of the tank when they have {@link #canDrain()} set to false}.
      */
+    @Nullable
     public FluidStack drainInternal(FluidStack resource, boolean doDrain)
     {
         if (resource == null || !resource.isFluidEqual(getFluid()))
@@ -250,6 +251,7 @@ public class FluidTank implements IFluidTank, IFluidHandler
      * Use this method to bypass the restrictions from {@link #canDrainFluidType(FluidStack)}
      * Meant for use by the owner of the tank when they have {@link #canDrain()} set to false}.
      */
+    @Nullable
     public FluidStack drainInternal(int maxDrain, boolean doDrain)
     {
         if (fluid == null || maxDrain <= 0)
@@ -343,9 +345,9 @@ public class FluidTank implements IFluidTank, IFluidHandler
      *
      * @see IFluidTankProperties#canDrainFluidType(FluidStack)
      */
-    public boolean canDrainFluidType(FluidStack fluid)
+    public boolean canDrainFluidType(@Nullable FluidStack fluid)
     {
-        return canDrain();
+        return fluid != null && canDrain();
     }
 
     protected void onContentsChanged()

src/main/java/net/minecraftforge/fluids/IFluidBlock.java

@@ -23,6 +23,7 @@ import net.minecraft.util.math.BlockPos;
 import net.minecraft.world.World;
 
 import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
 
 /**
  * Implement this interface on Block classes which represent world-placeable Fluids.
@@ -60,6 +61,7 @@ public interface IFluidBlock
      *            If false, the drain will only be simulated.
      * @return
      */
+    @Nullable
     FluidStack drain(World world, BlockPos pos, boolean doDrain);
 
     /**

src/main/java/net/minecraftforge/fluids/UniversalBucket.java

@@ -48,6 +48,7 @@ import net.minecraftforge.fml.relauncher.SideOnly;
 import net.minecraftforge.items.ItemHandlerHelper;
 
 import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
 
 /**
  * A universal bucket that can hold any liquid
@@ -103,7 +104,7 @@ public class UniversalBucket extends Item
 
     @SideOnly(Side.CLIENT)
     @Override
-    public void getSubItems(@Nonnull Item itemIn, @Nonnull CreativeTabs tab, @Nonnull NonNullList<ItemStack> subItems)
+    public void getSubItems(@Nonnull Item itemIn, @Nullable CreativeTabs tab, @Nonnull NonNullList<ItemStack> subItems)
     {
         for (Fluid fluid : FluidRegistry.getRegisteredFluids().values())
         {
@@ -276,6 +277,7 @@ public class UniversalBucket extends Item
         return bucket;
     }
 
+    @Nullable
     public FluidStack getFluid(@Nonnull ItemStack container)
     {
         return FluidStack.loadFluidStackFromNBT(container.getTagCompound());

src/main/java/net/minecraftforge/fluids/capability/wrappers/FluidBucketWrapper.java

@@ -96,7 +96,7 @@ public class FluidBucketWrapper implements IFluidHandlerItem, ICapabilityProvide
         }
     }
 
-    protected void setFluid(Fluid fluid) {
+    protected void setFluid(@Nullable Fluid fluid) {
         if (fluid == null)
         {
             container = new ItemStack(Items.BUCKET);

src/main/java/net/minecraftforge/fml/client/FMLClientHandler.java

@@ -135,6 +135,8 @@ import com.google.gson.JsonArray;
 import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
 
+import javax.annotation.Nullable;
+
 
 /**
  * Handles primary communication from hooked code into the system
@@ -512,7 +514,7 @@ public class FMLClientHandler implements IFMLSidedHandler
     }
 
     @Override
-    public void showGuiScreen(Object clientGuiElement)
+    public void showGuiScreen(@Nullable Object clientGuiElement)
     {
         GuiScreen gui = (GuiScreen) clientGuiElement;
         client.displayGuiScreen(gui);
@@ -813,6 +815,7 @@ public class FMLClientHandler implements IFMLSidedHandler
     private static final ResourceLocation iconSheet = new ResourceLocation("fml:textures/gui/icons.png");
     private static final CountDownLatch startupConnectionData = new CountDownLatch(1);
 
+    @Nullable
     public String enhanceServerListEntry(ServerListEntryNormal serverListEntry, ServerData serverEntry, int x, int width, int y, int relativeMouseX, int relativeMouseY)
     {
         String tooltip;

src/main/java/net/minecraftforge/fml/client/GuiModList.java

@@ -29,6 +29,7 @@ import java.util.Comparator;
 import java.util.List;
 import java.util.Map.Entry;
 
+import javax.annotation.Nullable;
 import javax.imageio.ImageIO;
 
 import net.minecraft.client.Minecraft;
@@ -84,6 +85,7 @@ public class GuiModList extends GuiScreen
             this.buttonID = buttonID;
         }
 
+        @Nullable
         public static SortType getTypeForButton(GuiButton button)
         {
             for (SortType t : values())
@@ -468,11 +470,12 @@ public class GuiModList extends GuiScreen
 
     private class Info extends GuiScrollingList
     {
+        @Nullable
         private ResourceLocation logoPath;
         private Dimension logoDims;
         private List<ITextComponent> lines = null;
 
-        public Info(int width, List<String> lines, ResourceLocation logoPath, Dimension logoDims)
+        public Info(int width, List<String> lines, @Nullable ResourceLocation logoPath, Dimension logoDims)
         {
             super(GuiModList.this.getMinecraftInstance(),
                   width,

src/main/java/net/minecraftforge/fml/client/IModGuiFactory.java

@@ -25,6 +25,8 @@ import net.minecraft.client.Minecraft;
 import net.minecraft.client.gui.Gui;
 import net.minecraft.client.gui.GuiScreen;
 
+import javax.annotation.Nullable;
+
 public interface IModGuiFactory {
     /**
      * Called when instantiated to initialize with the active minecraft instance.
@@ -85,6 +87,7 @@ public interface IModGuiFactory {
      * @param element The element we wish to paint for
      * @return The Handler for painting it
      */
+    @Nullable
     public RuntimeOptionGuiHandler getHandlerFor(RuntimeOptionCategoryElement element);
 
     /**

src/main/java/net/minecraftforge/fml/client/SplashProgress.java

@@ -38,6 +38,8 @@ import java.util.concurrent.Semaphore;
 import java.util.concurrent.locks.Lock;
 import java.util.concurrent.locks.ReentrantLock;
 
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
 import javax.imageio.ImageIO;
 import javax.imageio.ImageReader;
 import javax.imageio.stream.ImageInputStream;
@@ -731,12 +733,12 @@ public class SplashProgress
         private final int frames;
         private final int size;
 
-        public Texture(ResourceLocation location, ResourceLocation fallback)
+        public Texture(ResourceLocation location, @Nullable ResourceLocation fallback)
         {
             this(location, fallback, true);
         }
 
-        public Texture(ResourceLocation location, ResourceLocation fallback, boolean allowRP)
+        public Texture(ResourceLocation location, @Nullable ResourceLocation fallback, boolean allowRP)
         {
             InputStream s = null;
             try
@@ -881,14 +883,15 @@ public class SplashProgress
         }
 
         @Override
-        protected void bindTexture(ResourceLocation location)
+        protected void bindTexture(@Nonnull ResourceLocation location)
         {
             if(location != locationFontTexture) throw new IllegalArgumentException();
             fontTexture.bind();
         }
 
+        @Nonnull
         @Override
-        protected IResource getResource(ResourceLocation location) throws IOException
+        protected IResource getResource(@Nonnull ResourceLocation location) throws IOException
         {
             DefaultResourcePack pack = Minecraft.getMinecraft().mcDefaultResourcePack;
             return new SimpleResource(pack.getPackName(), location, pack.getInputStream(location), null, null);
@@ -920,7 +923,7 @@ public class SplashProgress
         }
     }
 
-    private static InputStream open(ResourceLocation loc, ResourceLocation fallback, boolean allowRP) throws IOException
+    private static InputStream open(ResourceLocation loc, @Nullable ResourceLocation fallback, boolean allowRP) throws IOException
     {
         if (!allowRP)
             return mcPack.getInputStream(loc);

src/main/java/net/minecraftforge/fml/client/config/DummyConfigElement.java

@@ -28,6 +28,8 @@ import net.minecraft.client.resources.I18n;
 import net.minecraftforge.fml.client.config.GuiConfigEntries.IConfigEntry;
 import net.minecraftforge.fml.client.config.GuiEditArrayEntries.IArrayEntry;
 
+import javax.annotation.Nullable;
+
 
 /**
  * This class's main purpose is to provide the necessary objects for a sample Config GUI for FML, although
@@ -56,6 +58,7 @@ public class DummyConfigElement implements IConfigElement
     protected boolean isListFixedLength = false;
     protected int maxListLength = -1;
     protected List<IConfigElement> childElements;
+    @Nullable
     protected Class<? extends IConfigEntry> configEntryClass;
     protected Class<? extends IArrayEntry> arrayEntryClass;
     
@@ -75,7 +78,7 @@ public class DummyConfigElement implements IConfigElement
             this(name, langKey, new ArrayList<IConfigElement>(), customListEntryClass);
         }
         
-        public DummyCategoryElement(String name, String langKey, List<IConfigElement> childElements, Class<? extends IConfigEntry> customListEntryClass)
+        public DummyCategoryElement(String name, String langKey, List<IConfigElement> childElements, @Nullable Class<? extends IConfigEntry> customListEntryClass)
         {
             super(name, null, ConfigGuiType.CONFIG_CATEGORY, langKey);
             this.childElements = childElements;
@@ -89,7 +92,7 @@ public class DummyConfigElement implements IConfigElement
      */
     public static class DummyListElement extends DummyConfigElement
     {
-        public DummyListElement(String name, Object[] defaultValues, ConfigGuiType type, String langKey, boolean isListFixedLength, int maxListLength, Pattern validStringPattern, Object minValue, Object maxValue)
+        public DummyListElement(String name, Object[] defaultValues, ConfigGuiType type, String langKey, boolean isListFixedLength, int maxListLength, @Nullable Pattern validStringPattern, @Nullable Object minValue, @Nullable Object maxValue)
         {
             super(name, null, type, langKey, minValue, maxValue);
             this.defaultValues = defaultValues;

src/main/java/net/minecraftforge/fml/client/config/GuiConfig.java

@@ -42,6 +42,8 @@ import net.minecraftforge.fml.common.eventhandler.Event.Result;
 
 import org.lwjgl.input.Keyboard;
 
+import javax.annotation.Nullable;
+
 /**
  * This class is the base GuiScreen for all config GUI screens. It can be extended by mods to provide the top-level config screen
  * that will be called when the Config button is clicked from the Main Menu Mods list.
@@ -55,6 +57,7 @@ public class GuiConfig extends GuiScreen
      */
     public final GuiScreen parentScreen;
     public String title = "Config GUI";
+    @Nullable
     public String titleLine2;
     public final List<IConfigElement> configElements;
     public final List<IConfigEntry> initEntries;
@@ -68,6 +71,7 @@ public class GuiConfig extends GuiScreen
      * if any configElements were changed (includes child screens). If not defined, the events will be posted if the parent gui is null
      * or if the parent gui is not an instance of GuiConfig.
      */
+    @Nullable
     public final String configID;
     public final boolean isWorldRunning;
     public final boolean allRequireWorldRestart;
@@ -154,8 +158,8 @@ public class GuiConfig extends GuiScreen
      * @param titleLine2 the desired title second line for this screen. Typically this is used to send the category name of the category
      *            currently being edited.
      */
-    public GuiConfig(GuiScreen parentScreen, List<IConfigElement> configElements, String modID, String configID,
-            boolean allRequireWorldRestart, boolean allRequireMcRestart, String title, String titleLine2)
+    public GuiConfig(GuiScreen parentScreen, List<IConfigElement> configElements, String modID, @Nullable String configID,
+            boolean allRequireWorldRestart, boolean allRequireMcRestart, String title, @Nullable String titleLine2)
     {
         this.mc = Minecraft.getMinecraft();
         this.parentScreen = parentScreen;

src/main/java/net/minecraftforge/fml/client/config/GuiMessageDialog.java

@@ -20,16 +20,17 @@
 package net.minecraftforge.fml.client.config;
 
 import net.minecraft.client.gui.GuiDisconnected;
-import net.minecraft.client.gui.GuiButton;
 import net.minecraft.client.gui.GuiScreen;
 import net.minecraft.client.resources.I18n;
 import net.minecraft.util.text.ITextComponent;
 
+import javax.annotation.Nullable;
+
 public class GuiMessageDialog extends GuiDisconnected
 {
     protected String buttonText;
 
-    public GuiMessageDialog(GuiScreen nextScreen, String title, ITextComponent message, String buttonText)
+    public GuiMessageDialog(@Nullable GuiScreen nextScreen, String title, ITextComponent message, String buttonText)
     {
         super(nextScreen, title, message);
         this.buttonText = buttonText;

src/main/java/net/minecraftforge/fml/client/config/GuiSlider.java

@@ -22,6 +22,8 @@ package net.minecraftforge.fml.client.config;
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.renderer.GlStateManager;
 
+import javax.annotation.Nullable;
+
 /**
  * This class is blatantly stolen from iChunUtils with permission.
  *
@@ -42,6 +44,7 @@ public class GuiSlider extends GuiButtonExt
     public double maxValue = 5.0D;
     public int precision = 1;
 
+    @Nullable
     public ISlider parent = null;
 
     public String suffix = "";
@@ -53,7 +56,7 @@ public class GuiSlider extends GuiButtonExt
         this(id, xPos, yPos, width, height, prefix, suf, minVal, maxVal, currentVal, showDec, drawStr, null);
     }
 
-    public GuiSlider(int id, int xPos, int yPos, int width, int height, String prefix, String suf, double minVal, double maxVal, double currentVal, boolean showDec, boolean drawStr, ISlider par)
+    public GuiSlider(int id, int xPos, int yPos, int width, int height, String prefix, String suf, double minVal, double maxVal, double currentVal, boolean showDec, boolean drawStr, @Nullable ISlider par)
     {
         super(id, xPos, yPos, width, height, prefix);
         minValue = minVal;

src/main/java/net/minecraftforge/fml/client/config/GuiUtils.java

@@ -36,7 +36,7 @@ import org.lwjgl.opengl.GL11;
 import java.util.ArrayList;
 import java.util.List;
 
-import javax.annotation.Nullable;
+import javax.annotation.Nonnull;
 
 /**
  * This class provides several methods and constants used by the Config GUI classes.
@@ -210,14 +210,15 @@ public class GuiUtils
         tessellator.draw();
     }
 
-    private static ItemStack cachedTooltipStack;
+    @Nonnull
+    private static ItemStack cachedTooltipStack = ItemStack.EMPTY;
 
     /**
      * Must be called from {@code GuiScreen.renderToolTip} before {@code GuiScreen.drawHoveringText} is called.
      * 
      * @param stack The stack for which a tooltip is about to be drawn.
      */
-    public static void preItemToolTip(ItemStack stack)
+    public static void preItemToolTip(@Nonnull ItemStack stack)
     {
         cachedTooltipStack = stack;
     }
@@ -227,7 +228,7 @@ public class GuiUtils
      */
     public static void postItemToolTip()
     {
-        cachedTooltipStack = null;
+        cachedTooltipStack = ItemStack.EMPTY;
     }
 
     /**
@@ -255,8 +256,7 @@ public class GuiUtils
      * 
      * @see #drawHoveringText(List, int, int, int, int, int, FontRenderer)
      */
-    public static void drawHoveringText(@Nullable final ItemStack stack, List<String> textLines, int mouseX, int mouseY, int screenWidth, int screenHeight,
-            int maxTextWidth, FontRenderer font)
+    public static void drawHoveringText(@Nonnull final ItemStack stack, List<String> textLines, int mouseX, int mouseY, int screenWidth, int screenHeight, int maxTextWidth, FontRenderer font)
     {
         if (!textLines.isEmpty())
         {

src/main/java/net/minecraftforge/fml/client/event/ConfigChangedEvent.java

@@ -22,6 +22,8 @@ package net.minecraftforge.fml.client.event;
 import net.minecraftforge.fml.common.eventhandler.Event;
 import net.minecraftforge.fml.common.eventhandler.Event.HasResult;
 
+import javax.annotation.Nullable;
+
 /**
  * These events are posted from the GuiConfig screen when the done button is pressed. The events are only posted
  * if the parent screen is not an instance of GuiConfig or if the configID field has been set for
@@ -39,9 +41,10 @@ public class ConfigChangedEvent extends Event
     private final String  modID;
     private final boolean isWorldRunning;
     private final boolean requiresMcRestart;
+    @Nullable
     private final String configID;
 
-    public ConfigChangedEvent(String modID, String configID, boolean isWorldRunning, boolean requiresMcRestart)
+    public ConfigChangedEvent(String modID, @Nullable String configID, boolean isWorldRunning, boolean requiresMcRestart)
     {
         this.modID = modID;
         this.configID = configID;
@@ -76,6 +79,7 @@ public class ConfigChangedEvent extends Event
     /**
      * A String identifier for this ConfigChangedEvent.
      */
+    @Nullable
     public String getConfigID()
     {
         return configID;
@@ -92,7 +96,7 @@ public class ConfigChangedEvent extends Event
      */
     public static class OnConfigChangedEvent extends ConfigChangedEvent
     {
-        public OnConfigChangedEvent(String modID, String configID, boolean isWorldRunning, boolean requiresMcRestart)
+        public OnConfigChangedEvent(String modID, @Nullable String configID, boolean isWorldRunning, boolean requiresMcRestart)
         {
             super(modID, configID, isWorldRunning, requiresMcRestart);
         }
@@ -104,7 +108,7 @@ public class ConfigChangedEvent extends Event
      */
     public static class PostConfigChangedEvent extends ConfigChangedEvent
     {
-        public PostConfigChangedEvent(String modID, String configID, boolean isWorldRunning, boolean requiresMcRestart)
+        public PostConfigChangedEvent(String modID, @Nullable String configID, boolean isWorldRunning, boolean requiresMcRestart)
         {
             super(modID, configID, isWorldRunning, requiresMcRestart);
         }

src/main/java/net/minecraftforge/fml/common/CertificateHelper.java

@@ -43,7 +43,7 @@ public class CertificateHelper {
         }
         catch (Exception e)
         {
-            return null;
+            return "CERTIFICATE FINGERPRINT EXCEPTION";
         }
     }
 
@@ -58,7 +58,7 @@ public class CertificateHelper {
         }
         catch (Exception e)
         {
-            return null;
+            return "CERTIFICATE FINGERPRINT EXCEPTION";
         }
     }
 

src/main/java/net/minecraftforge/fml/common/DummyModContainer.java

@@ -34,6 +34,8 @@ import net.minecraftforge.fml.common.versioning.VersionRange;
 import com.google.common.collect.ImmutableList;
 import com.google.common.eventbus.EventBus;
 
+import javax.annotation.Nullable;
+
 public class DummyModContainer implements ModContainer
 {
     private ModMetadata md;
@@ -164,6 +166,7 @@ public class DummyModContainer implements ModContainer
     }
 
     @Override
+    @Nullable
     public Certificate getSigningCertificate()
     {
         return null;

src/main/java/net/minecraftforge/fml/common/FMLCommonHandler.java

@@ -81,6 +81,8 @@ import com.google.common.collect.MapMaker;
 import com.google.common.collect.Maps;
 import com.google.common.collect.Sets;
 
+import javax.annotation.Nullable;
+
 
 /**
  * The main class for non-obfuscated hook handling code
@@ -709,6 +711,7 @@ public class FMLCommonHandler
      * @param inputstream Input stream containing the lang file.
      * @return A new InputStream that vanilla uses to load normal Lang files, Null if this is a 'enhanced' file and loading is done.
      */
+    @Nullable
     public InputStream loadLanguage(Map<String, String> table, InputStream inputstream) throws IOException
     {
         byte[] data = IOUtils.toByteArray(inputstream);

src/main/java/net/minecraftforge/fml/common/FMLContainer.java

@@ -52,6 +52,8 @@ import org.apache.logging.log4j.Level;
 import com.google.common.eventbus.EventBus;
 import com.google.common.eventbus.Subscribe;
 
+import javax.annotation.Nullable;
+
 /**
  * @author cpw
  *
@@ -343,6 +345,7 @@ public final class FMLContainer extends DummyModContainer implements WorldAccess
 
 
     @Override
+    @Nullable
     public Certificate getSigningCertificate()
     {
         Certificate[] certificates = getClass().getProtectionDomain().getCodeSource().getCertificates();

src/main/java/net/minecraftforge/fml/common/FMLModContainer.java

@@ -77,6 +77,8 @@ import com.google.common.collect.Sets;
 import com.google.common.eventbus.EventBus;
 import com.google.common.eventbus.Subscribe;
 
+import javax.annotation.Nullable;
+
 public class FMLModContainer implements ModContainer
 {
     private Object modInstance;
@@ -280,6 +282,7 @@ public class FMLModContainer implements ModContainer
         }
     }
 
+    @Nullable
     public Properties searchForVersionProperties()
     {
         try
@@ -391,6 +394,7 @@ public class FMLModContainer implements ModContainer
         }
     }
 
+    @Nullable
     @SuppressWarnings("unchecked")
     private Method gatherAnnotations(Class<?> clazz) throws Exception
     {

src/main/java/net/minecraftforge/fml/common/InjectedModContainer.java

@@ -31,6 +31,8 @@ import net.minecraftforge.fml.common.versioning.VersionRange;
 
 import com.google.common.eventbus.EventBus;
 
+import javax.annotation.Nullable;
+
 public class InjectedModContainer implements ModContainer
 {
     private File source;
@@ -150,6 +152,7 @@ public class InjectedModContainer implements ModContainer
         return wrappedContainer.acceptableMinecraftVersionRange();
     }
 
+    @Nullable
     public WorldAccessContainer getWrappedWorldAccessContainer()
     {
         if (wrappedContainer instanceof WorldAccessContainer)
@@ -163,6 +166,7 @@ public class InjectedModContainer implements ModContainer
     }
 
     @Override
+    @Nullable
     public Certificate getSigningCertificate()
     {
         return wrappedContainer.getSigningCertificate();

src/main/java/net/minecraftforge/fml/common/LoadController.java

@@ -55,6 +55,8 @@ import com.google.common.eventbus.Subscribe;
 import com.google.common.eventbus.SubscriberExceptionHandler;
 import com.google.common.eventbus.SubscriberExceptionContext;
 
+import javax.annotation.Nullable;
+
 public class LoadController
 {
     private Loader loader;
@@ -198,12 +200,13 @@ public class LoadController
 
     }
 
+    @Nullable
     public ModContainer activeContainer()
     {
         return activeContainer != null ? activeContainer : findActiveContainerFromStack();
     }
 
-    void forceActiveContainer(ModContainer container)
+    void forceActiveContainer(@Nullable ModContainer container)
     {
         activeContainer = container;
     }
@@ -237,7 +240,7 @@ public class LoadController
             }
         }
         activeContainer = mc;
-        stateEvent.applyModContainer(activeContainer());
+        stateEvent.applyModContainer(mc);
         ThreadContext.put("mod", modId);
         FMLLog.log(modId, Level.TRACE, "Sending event %s to mod %s", stateEvent.getEventType(), modId);
         eventChannels.get(modId).post(stateEvent);
@@ -358,6 +361,7 @@ public class LoadController
         this.state = newState;
     }
 
+    @Nullable
     private ModContainer findActiveContainerFromStack()
     {
         for (Class<?> c : getCallingStack())

src/main/java/net/minecraftforge/fml/common/Loader.java

@@ -90,6 +90,8 @@ import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
 import com.google.gson.JsonParser;
 
+import javax.annotation.Nullable;
+
 /**
  * The loader class performs the actual loading of the mod code from disk.
  *
@@ -887,6 +889,7 @@ public class Loader
         return getModObjectList().inverse();
     }
 
+    @Nullable
     public ModContainer activeModContainer()
     {
         return modController != null ? modController.activeContainer() : null;
@@ -1162,7 +1165,7 @@ public class Loader
         return modController != null ? modController.getState() : LoaderState.NOINIT;
     }
 
-    public void setActiveModContainer(ModContainer container)
+    public void setActiveModContainer(@Nullable ModContainer container)
     {
         this.modController.forceActiveContainer(container);
     }

src/main/java/net/minecraftforge/fml/common/MetadataCollection.java

@@ -41,13 +41,15 @@ import com.google.gson.TypeAdapter;
 import com.google.gson.stream.JsonReader;
 import com.google.gson.stream.JsonWriter;
 
+import javax.annotation.Nullable;
+
 public class MetadataCollection
 {
     private String modListVersion;
     private ModMetadata[] modList;
     private Map<String, ModMetadata> metadatas = Maps.newHashMap();
 
-    public static MetadataCollection from(InputStream inputStream, String sourceName)
+    public static MetadataCollection from(@Nullable InputStream inputStream, String sourceName)
     {
         if (inputStream == null)
         {

src/main/java/net/minecraftforge/fml/common/MinecraftDummyContainer.java

@@ -28,6 +28,8 @@ import net.minecraftforge.fml.common.versioning.VersionRange;
 import net.minecraftforge.fml.relauncher.FMLLaunchHandler;
 import net.minecraftforge.fml.relauncher.Side;
 
+import javax.annotation.Nullable;
+
 public class MinecraftDummyContainer extends DummyModContainer
 {
 
@@ -65,6 +67,7 @@ public class MinecraftDummyContainer extends DummyModContainer
     }
 
     @Override
+    @Nullable
     public Certificate getSigningCertificate()
     {
         if (FMLLaunchHandler.side() != Side.CLIENT)
@@ -76,7 +79,7 @@ public class MinecraftDummyContainer extends DummyModContainer
             Certificate[] certificates = cbr.getProtectionDomain().getCodeSource().getCertificates();
             return certificates != null ? certificates[0] : null;
         }
-        catch (Exception e){} // Errors don't matter just return null.
+        catch (Exception ignored){} // Errors don't matter just return null.
         return null;
     }
 }

src/main/java/net/minecraftforge/fml/common/ModContainer.java

@@ -32,6 +32,8 @@ import net.minecraftforge.fml.common.versioning.VersionRange;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.eventbus.EventBus;
 
+import javax.annotation.Nullable;
+
 /**
  * The container that wraps around mods in the system.
  * <p>
@@ -141,6 +143,7 @@ public interface ModContainer
 
     VersionRange acceptableMinecraftVersionRange();
 
+    @Nullable
     Certificate getSigningCertificate();
 
     public static final Map<String,String> EMPTY_PROPERTIES = ImmutableMap.of();

src/main/java/net/minecraftforge/fml/common/ModContainerFactory.java

@@ -34,6 +34,8 @@ import org.objectweb.asm.Type;
 import com.google.common.base.Throwables;
 import com.google.common.collect.Maps;
 
+import javax.annotation.Nullable;
+
 public class ModContainerFactory
 {
     public static Map<Type, Constructor<? extends ModContainer>> modTypes = Maps.newHashMap();
@@ -58,6 +60,8 @@ public class ModContainerFactory
             Throwables.propagate(e);
         }
     }
+
+    @Nullable
     public ModContainer build(ASMModParser modParser, File modSource, ModCandidate container)
     {
         String className = modParser.getASMType().getClassName();

src/main/java/net/minecraftforge/fml/common/StartupQuery.java

@@ -24,6 +24,8 @@ import java.util.concurrent.atomic.AtomicBoolean;
 
 import net.minecraft.server.MinecraftServer;
 
+import javax.annotation.Nullable;
+
 public class StartupQuery {
     // internal class/functionality, do not use
 
@@ -80,12 +82,13 @@ public class StartupQuery {
     private static volatile boolean aborted = false;
 
 
-    private StartupQuery(String text, AtomicBoolean result)
+    private StartupQuery(String text, @Nullable AtomicBoolean result)
     {
         this.text = text;
         this.result = result;
     }
 
+    @Nullable
     public Boolean getResult()
     {
         return result == null ? null : result.get();
@@ -159,6 +162,7 @@ public class StartupQuery {
     }
 
     private String text;
+    @Nullable
     private AtomicBoolean result;
     private CountDownLatch signal = new CountDownLatch(1);
     private volatile boolean synchronous;

src/main/java/net/minecraftforge/fml/common/asm/ASMTransformerWrapper.java

@@ -47,6 +47,8 @@ import com.google.common.cache.CacheLoader;
 import com.google.common.cache.LoadingCache;
 import com.google.common.collect.Maps;
 
+import javax.annotation.Nullable;
+
 public class ASMTransformerWrapper
 {
     private static final Map<String, String> wrapperModMap = Maps.newHashMap();
@@ -80,6 +82,7 @@ public class ASMTransformerWrapper
 
     private static class ASMGenHandler extends URLStreamHandler
     {
+        @Nullable
         protected URLConnection openConnection(URL url) throws IOException
         {
             String file = url.getFile();
@@ -125,6 +128,7 @@ public class ASMTransformerWrapper
         }
 
         @Override
+        @Nullable
         public Permission getPermission()
         {
             return null;

src/main/java/net/minecraftforge/fml/common/asm/transformers/deobf/FMLDeobfuscatingRemapper.java

@@ -54,6 +54,8 @@ import com.google.common.collect.Sets;
 import com.google.common.io.CharSource;
 import com.google.common.io.Files;
 
+import javax.annotation.Nullable;
+
 public class FMLDeobfuscatingRemapper extends Remapper {
     public static final FMLDeobfuscatingRemapper INSTANCE = new FMLDeobfuscatingRemapper();
 
@@ -198,12 +200,13 @@ public class FMLDeobfuscatingRemapper extends Remapper {
     /*
      * Cache the field descriptions for classes so we don't repeatedly reload the same data again and again
      */
-    private Map<String,Map<String,String>> fieldDescriptions = Maps.newHashMap();
+    private final Map<String,Map<String,String>> fieldDescriptions = Maps.newHashMap();
 
     // Cache null values so we don't waste time trying to recompute classes with no field or method maps
     private Set<String> negativeCacheMethods = Sets.newHashSet();
     private Set<String> negativeCacheFields = Sets.newHashSet();
 
+    @Nullable
     private String getFieldType(String owner, String name)
     {
         if (fieldDescriptions.containsKey(owner))
@@ -283,12 +286,12 @@ public class FMLDeobfuscatingRemapper extends Remapper {
     }
 
     @Override
-    public String mapFieldName(String owner, String name, String desc)
+    public String mapFieldName(String owner, String name, @Nullable String desc)
     {
         return mapFieldName(owner, name, desc, false);
     }
 
-    String mapFieldName(String owner, String name, String desc, boolean raw)
+    String mapFieldName(String owner, String name, @Nullable String desc, boolean raw)
     {
         if (classNameBiMap == null || classNameBiMap.isEmpty())
         {
@@ -350,6 +353,7 @@ public class FMLDeobfuscatingRemapper extends Remapper {
     }
     
     @Override
+    @Nullable
     public String mapSignature(String signature, boolean typeSignature)
     {
         // JDT decorates some lambdas with this and SignatureReader chokes on it
@@ -430,7 +434,7 @@ public class FMLDeobfuscatingRemapper extends Remapper {
             e.printStackTrace();
         }
     }
-    public void mergeSuperMaps(String name, String superName, String[] interfaces)
+    public void mergeSuperMaps(String name, @Nullable String superName, String[] interfaces)
     {
 //        System.out.printf("Computing super maps for %s: %s %s\n", name, superName, Arrays.asList(interfaces));
         if (classNameBiMap == null || classNameBiMap.isEmpty())
@@ -483,6 +487,7 @@ public class FMLDeobfuscatingRemapper extends Remapper {
         return ImmutableSet.copyOf(classNameBiMap.keySet());
     }
 
+    @Nullable
     public String getStaticFieldType(String oldType, String oldName, String newType, String newName)
     {
         String fType = getFieldType(newType, newName);

src/main/java/net/minecraftforge/fml/common/discovery/ASMDataTable.java

@@ -35,6 +35,8 @@ import com.google.common.collect.Multimap;
 import com.google.common.collect.Multimaps;
 import com.google.common.collect.SetMultimap;
 
+import javax.annotation.Nullable;
+
 public class ASMDataTable
 {
     public final static class ASMData implements Cloneable
@@ -45,7 +47,7 @@ public class ASMDataTable
         private String objectName;
         private int classVersion;
         private Map<String,Object> annotationInfo;
-        public ASMData(ModCandidate candidate, String annotationName, String className, String objectName, Map<String,Object> info)
+        public ASMData(ModCandidate candidate, String annotationName, String className, @Nullable String objectName, @Nullable Map<String,Object> info)
         {
             this.candidate = candidate;
             this.annotationName = annotationName;
@@ -128,7 +130,7 @@ public class ASMDataTable
         return globalAnnotationData.get(annotation);
     }
 
-    public void addASMData(ModCandidate candidate, String annotation, String className, String objectName, Map<String,Object> annotationInfo)
+    public void addASMData(ModCandidate candidate, String annotation, String className, @Nullable String objectName, @Nullable Map<String,Object> annotationInfo)
     {
         globalAnnotationData.put(annotation, new ASMData(candidate, annotation, className, objectName, annotationInfo));
     }
@@ -148,6 +150,7 @@ public class ASMDataTable
         return this.packageMap.get(pkg);
     }
 
+    @Nullable
     public static String getOwnerModID(Set<ASMData> mods, ASMData targ)
     {
         if (mods.size() == 1) {

src/main/java/net/minecraftforge/fml/common/discovery/DirectoryDiscoverer.java

@@ -39,6 +39,8 @@ import org.apache.logging.log4j.Level;
 import com.google.common.base.Throwables;
 import com.google.common.collect.Lists;
 
+import javax.annotation.Nullable;
+
 public class DirectoryDiscoverer implements ITypeDiscoverer
 {
     private class ClassFilter implements FileFilter
@@ -66,7 +68,7 @@ public class DirectoryDiscoverer implements ITypeDiscoverer
         return found;
     }
 
-    public void exploreFileSystem(String path, File modDir, List<ModContainer> harvestedMods, ModCandidate candidate, MetadataCollection mc)
+    public void exploreFileSystem(String path, File modDir, List<ModContainer> harvestedMods, ModCandidate candidate, @Nullable MetadataCollection mc)
     {
         if (path.length() == 0)
         {

src/main/java/net/minecraftforge/fml/common/event/FMLInterModComms.java

@@ -35,6 +35,8 @@ import com.google.common.collect.ArrayListMultimap;
 import com.google.common.collect.ImmutableList;
 import org.apache.logging.log4j.Level;
 
+import javax.annotation.Nonnull;
+
 /**
  * Simple intermod communications to receive simple messages directed at you
  * from other mods
@@ -91,20 +93,22 @@ public class FMLInterModComms {
         /**
          * This field, and {@link #value} are both at the mod's discretion
          */
+        @Nonnull
         public final String key;
         /**
          * This field, and {@link #key} are both at the mod's discretion
          */
+        @Nonnull
         private final Object value;
 
-        private IMCMessage(String key, Object value)
+        private IMCMessage(@Nonnull String key, @Nonnull Object value)
         {
             this.key = key;
             this.value = value;
             this.isFunction = false;
         }
 
-        private IMCMessage(String key, String value, boolean isFunction) {
+        private IMCMessage(@Nonnull String key, @Nonnull String value, boolean isFunction) {
             this.key = key;
             this.value = value;
             this.isFunction = isFunction;
@@ -164,6 +168,7 @@ public class FMLInterModComms {
          * @throws ClassCastException if this message doesn't contain an Itemstack value
          * @return The Itemstack value
          */
+        @Nonnull
         public ItemStack getItemStackValue()
         {
             return (ItemStack) value;

src/main/java/net/minecraftforge/fml/common/event/FMLPostInitializationEvent.java

@@ -70,14 +70,14 @@ public class FMLPostInitializationEvent extends FMLStateEvent
                 @Nullable
                 @Override
                 public Class<?> apply(@Nullable Object input) {
-                    return input.getClass();
+                    return input == null ? null : input.getClass();
                 }
             }).toArray(new Class[0]);
             try
             {
                 Class<?> clz = Class.forName(className,true,Loader.instance().getModClassLoader());
                 Constructor<?> ct = clz.getConstructor(args);
-                return Optional.fromNullable(ct.newInstance(arguments));
+                return Optional.of(ct.newInstance(arguments));
             }
             catch (Exception e)
             {

src/main/java/net/minecraftforge/fml/common/event/FMLPreInitializationEvent.java

@@ -33,6 +33,8 @@ import net.minecraftforge.fml.common.discovery.ASMDataTable;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
+import javax.annotation.Nullable;
+
 /**
  * Called before {@link FMLInitializationEvent} during mod startup.
  *
@@ -132,6 +134,7 @@ public class FMLPreInitializationEvent extends FMLStateEvent
      * such as a unique version number from a properties file shipped as part of the distributable.
      * @return A properties object if one exists, else null
      */
+    @Nullable
     public Properties getVersionProperties()
     {
         if (this.modContainer instanceof FMLModContainer)

src/main/java/net/minecraftforge/fml/common/eventhandler/Event.java

@@ -153,7 +153,7 @@ public class Event
 
     public void setPhase(@Nonnull EventPriority value)
     {
-        Preconditions.checkArgument(value != null, "setPhase argument must not be null");
+        Preconditions.checkNotNull(value, "setPhase argument must not be null");
         int prev = phase == null ? -1 : phase.ordinal();
         Preconditions.checkArgument(prev < value.ordinal(), "Attempted to set event phase to %s when already %s", value, phase);
         phase = value;

src/main/java/net/minecraftforge/fml/common/eventhandler/EventBus.java

@@ -59,7 +59,7 @@ public class EventBus implements IEventExceptionHandler
     public EventBus(@Nonnull IEventExceptionHandler handler)
     {
         this();
-        Preconditions.checkArgument(handler != null, "EventBus exception handler can not be null");
+        Preconditions.checkNotNull(handler, "EventBus exception handler can not be null");
         exceptionHandler = handler;
     }
 

src/main/java/net/minecraftforge/fml/common/eventhandler/ListenerList.java

@@ -23,12 +23,15 @@ import java.util.*;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Lists;
 
+import javax.annotation.Nullable;
+
 
 public class ListenerList
 {
     private static ImmutableList<ListenerList> allLists = ImmutableList.of();
     private static int maxSize = 0;
 
+    @Nullable
     private ListenerList parent;
     private ListenerListInst[] lists = new ListenerListInst[0];
 
@@ -37,7 +40,7 @@ public class ListenerList
         this(null);
     }
 
-    public ListenerList(ListenerList parent)
+    public ListenerList(@Nullable ListenerList parent)
     {
         // parent needs to be set before resize !
         this.parent = parent;

src/main/java/net/minecraftforge/fml/common/network/ByteBufUtils.java

@@ -30,6 +30,8 @@ import com.google.common.base.Throwables;
 
 import io.netty.buffer.ByteBuf;
 
+import javax.annotation.Nullable;
+
 /**
  * Utilities for interacting with {@link ByteBuf}.
  * @author cpw
@@ -203,6 +205,7 @@ public class ByteBufUtils {
      * @param from The buffer to read from
      * @return The read tag
      */
+    @Nullable
     public static NBTTagCompound readTag(ByteBuf from)
     {
         PacketBuffer pb = new PacketBuffer(from);

src/main/java/net/minecraftforge/fml/common/network/FMLEmbeddedChannel.java

@@ -31,6 +31,8 @@ import net.minecraftforge.fml.common.network.FMLOutboundHandler.OutboundTarget;
 import net.minecraftforge.fml.common.network.internal.FMLProxyPacket;
 import net.minecraftforge.fml.relauncher.Side;
 
+import javax.annotation.Nullable;
+
 /**
  * Utility wrapper around {@link EmbeddedChannel}. Provides some convenience methods
  * associated with the specific needs of FML network handling.
@@ -72,6 +74,7 @@ public class FMLEmbeddedChannel extends EmbeddedChannel {
         return pkt;
     }
 
+    @Nullable
     public String findChannelHandlerNameForType(Class<? extends ChannelHandler> type)
     {
         String targetName = null;

src/main/java/net/minecraftforge/fml/common/network/FMLEventChannel.java

@@ -33,6 +33,8 @@ import net.minecraftforge.fml.common.eventhandler.SubscribeEvent;
 import net.minecraftforge.fml.common.network.internal.FMLProxyPacket;
 import net.minecraftforge.fml.relauncher.Side;
 
+import javax.annotation.Nullable;
+
 /**
  * An event driven network channel, using {@link FMLNetworkEvent.CustomPacketEvent} and {@link FMLNetworkEvent.CustomNetworkEvent}
  * to deliver messages to an event listener. There is one "bus" for each channel, due to the
@@ -57,6 +59,7 @@ public class FMLEventChannel {
         SERVER()
         {
             @Override
+            @Nullable
             FMLNetworkEvent.CustomPacketEvent<?> make(FMLProxyPacket msg)
             {
                 FMLNetworkEvent.CustomPacketEvent<?> event = null;
@@ -71,6 +74,7 @@ public class FMLEventChannel {
         CLIENT()
         {
             @Override
+            @Nullable
             FMLNetworkEvent.CustomPacketEvent<?> make(FMLProxyPacket msg)
             {
                 FMLNetworkEvent.CustomPacketEvent<?> event = null;
@@ -87,6 +91,7 @@ public class FMLEventChannel {
                 return event;
             }
         };
+        @Nullable
         abstract FMLNetworkEvent.CustomPacketEvent<?> make(FMLProxyPacket msg);
     }
 

src/main/java/net/minecraftforge/fml/common/network/FMLOutboundHandler.java

@@ -40,6 +40,8 @@ import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Sets;
 
+import javax.annotation.Nullable;
+
 public class FMLOutboundHandler extends ChannelOutboundHandlerAdapter {
     public static final AttributeKey<OutboundTarget> FML_MESSAGETARGET = AttributeKey.valueOf("fml:outboundTarget");
     public static final AttributeKey<Object> FML_MESSAGETARGETARGS = AttributeKey.valueOf("fml:outboundTargetArgs");
@@ -59,6 +61,7 @@ public class FMLOutboundHandler extends ChannelOutboundHandlerAdapter {
             }
 
             @Override
+            @Nullable
             public List<NetworkDispatcher> selectNetworks(Object args, ChannelHandlerContext context, FMLProxyPacket packet)
             {
                 return null;
@@ -253,6 +256,7 @@ public class FMLOutboundHandler extends ChannelOutboundHandlerAdapter {
         }
         public final ImmutableSet<Side> allowed;
         public abstract void validateArgs(Object args);
+        @Nullable
         public abstract List<NetworkDispatcher> selectNetworks(Object args, ChannelHandlerContext context, FMLProxyPacket packet);
     }
 

src/main/java/net/minecraftforge/fml/common/network/NetworkRegistry.java

@@ -50,6 +50,8 @@ import net.minecraftforge.fml.relauncher.Side;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.Maps;
 
+import javax.annotation.Nullable;
+
 /**
  * @author cpw
  *
@@ -242,6 +244,7 @@ public enum NetworkRegistry
      * @param z Z coord
      * @return The server side GUI object (An instance of {@link Container})
      */
+    @Nullable
     public Container getRemoteGuiContainer(ModContainer mc, EntityPlayerMP player, int modGuiId, World world, int x, int y, int z)
     {
         IGuiHandler handler = serverGuiHandlers.get(mc);
@@ -267,6 +270,7 @@ public enum NetworkRegistry
      * @param z Z coord
      * @return The client side GUI object (An instance of {@link net.minecraft.client.gui.Gui})
      */
+    @Nullable
     public Object getLocalGuiContainer(ModContainer mc, EntityPlayer player, int modGuiId, World world, int x, int y, int z)
     {
         IGuiHandler handler = clientGuiHandlers.get(mc);
@@ -291,7 +295,7 @@ public enum NetworkRegistry
      * @param remoteVersionRange the acceptable remote range
      * @param asmHarvestedData internal data
      */
-    public void register(ModContainer fmlModContainer, Class<?> clazz, String remoteVersionRange, ASMDataTable asmHarvestedData)
+    public void register(ModContainer fmlModContainer, Class<?> clazz, @Nullable String remoteVersionRange, ASMDataTable asmHarvestedData)
     {
         NetworkModHolder networkModHolder = new NetworkModHolder(fmlModContainer, clazz, remoteVersionRange, asmHarvestedData);
         registry.put(fmlModContainer, networkModHolder);