Here you can find the source of nullOrEmpty(Collection> tested)
public static boolean nullOrEmpty(Collection<?> tested)
//package com.java2s; //License from project: Open Source License import java.util.Collection; public class Main { public static boolean nullOrEmpty(Collection<?> tested) { return ((tested == null) || tested.isEmpty()); }/*from ww w. j a va2 s . c o m*/ }