FluidIngredient that facilitates accepting either a single, or multiple IFluidStacks, com.blamejared.crafttweaker.impl.tag.MCTag
Importing the class
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 at the very top of the file.
FluidIngredient implements the following interfaces. That means all methods defined in these interfaces are also available in FluidIngredient