Here you can find the source of assertNotNull(String fieldName, Object object)
private static void assertNotNull(String fieldName, Object object)
//package com.java2s; //License from project: Open Source License public class Main { private static void assertNotNull(String fieldName, Object object) { //if(object == null) // throw new DetailedNullPointerException(fieldName); //else/*from w w w. j a va2 s . co m*/ return; } }