The IItemDestroySpeed function can be added to an Item and will determine the item’s block breaking speed.

Importing the package

It might be required for you to import the package if you encounter any issues, so better be safe than sorry and add the import.
import mods.contenttweaker.IItemDestroySpeed;


The IItemDestroySpeed is a function with the following parameters:

The function needs to return a float value.