Represents an item stack in the world.

It might be required for you to import the package if you encounter any issues (like casting an Array), so better be safe than sorry and add the import.
import crafttweaker.entity.IEntityItem;

IEntityItem extends IEntity. That means all functions available to IEntities also are available to IEntityItem.

ZenGetter/ZenSetter	Tipo
ZenGetter/ZenSetter item	Tipo IItemStack