Optimize IngredientMatcherFluidStack#isEmpty method

Author: rubensworks

src/main/java/org/cyclops/commoncapabilities/ingredient/IngredientMatcherFluidStack.java

@@ -59,6 +59,11 @@ public FluidStack getEmptyInstance() {
         return FluidStack.EMPTY;
     }
 
+    @Override
+    public boolean isEmpty(FluidStack instance) {
+        return instance.isEmpty();
+    }
+
     @Override
     public int hash(FluidStack instance) {
         if (instance.isEmpty()) {