How to write a method using Sets [on hold]

I was given an assignment to write a sets method that takes the difference of two sets and makes a third set with the difference. If somebody can please provide me with feedback on how I can start it I would greatly appreciate it.

Thank you!

Write a static method named difference that takes two Sets of Integers as parameters C and D and returns a new Set of Integers that contains C - D. The original Sets C and D should be the same after the method is finished.