Here you can find the source of assertNotNull(Object obj, String name)
private static void assertNotNull(Object obj, String name)
//package com.java2s; //License from project: Apache License public class Main { private static void assertNotNull(Object obj, String name) { if (obj == null) { throw new IllegalArgumentException("Null " + name + " arguments are not accepted!"); }/*from w ww . j a v a 2 s. com*/ } }