Removed superfluous IAEStack methods

src/main/java/appeng/fluids/util/AEFluidStack.java

@@ -152,16 +152,6 @@ public final class AEFluidStack extends AEStack<IAEFluidStack> implements IAEFlu
         return dup;
     }
 
-    @Override
-    public boolean isItem() {
-        return false;
-    }
-
-    @Override
-    public boolean isFluid() {
-        return true;
-    }
-
     @Override
     public IStorageChannel<IAEFluidStack> getChannel() {
         return AEApi.instance().storage().getStorageChannel(IFluidStorageChannel.class);

src/main/java/appeng/util/item/AEItemStack.java

@@ -152,16 +152,6 @@ public final class AEItemStack extends AEStack<IAEItemStack> implements IAEItemS
         return new AEItemStack(this);
     }
 
-    @Override
-    public boolean isItem() {
-        return true;
-    }
-
-    @Override
-    public boolean isFluid() {
-        return false;
-    }
-
     @Override
     public IStorageChannel<IAEItemStack> getChannel() {
         return AEApi.instance().storage().getStorageChannel(IItemStorageChannel.class);