Here you can find the source of minus(List
public static <T> List<T> minus(List<T> initialList, List<T> elementsToRemove)
//package com.java2s; import java.util.*; public class Main { public static <T> List<T> minus(List<T> initialList, List<T> elementsToRemove) { List<T> minusedList = new ArrayList<T>(initialList); minusedList.removeAll(elementsToRemove); return minusedList; }// w w w . ja v a 2s . c om }