An IWeightedIngredient is an ingredient with a percentage. It is the subclass of WeightedItemStack, WeightedLiquidStack and WeightedOreDictEntry.

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.item.IWeightedIngredient;

ZenGetter	역할	반환 타입
ZenGetter ingredient	역할 Returns the associated IIngredient	반환 타입 IIngredient
ZenGetter chance	역할 Returns the stack's chance as decimal (e.g. 0.2)	반환 타입 float
ZenGetter percent	역할 Returns the stack's chance as percentage (e.g. 20.0)	반환 타입 float