Here you can find the source of isEmpty(List extends Object> list)
public static boolean isEmpty(List<? extends Object> list)
//package com.java2s; //License from project: Open Source License import java.util.List; import java.util.Map; public class Main { /**// w ww .j a v a 2 s. c o m * Return true if this map is null or it's empty. * * @param map * @return */ public static boolean isEmpty(Map<? extends Object, ? extends Object> map) { return map == null || map.isEmpty(); } public static boolean isEmpty(List<? extends Object> list) { return list == null || list.isEmpty(); } }