Here you can find the source of removeRightSet(Collection left, Collection right)
public static Collection removeRightSet(Collection left, Collection right)
//package com.java2s; import java.util.*; public class Main { public static Collection removeRightSet(Collection left, Collection right) { Collection set = new ArrayList(left); set.removeAll(right);//w ww .jav a2 s.co m return set; } }