Here you can find the source of assertIsNull(Object obj)
public static void assertIsNull(Object obj)
//package com.java2s; /**/*w w w .j a v a2 s .c o m*/ * <copyright> * * Copyright (c) 2005, 2006, 2007, 2008 Springsite BV (The Netherlands) and others * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/epl-v10.html * * Contributors: * Martin Taal - Initial API and implementation * * </copyright> * * $Id: AssertUtil.java,v 1.7 2009/03/30 07:53:04 mtaal Exp $ */ public class Main { /** Asserts that the passed entry is null */ public static void assertIsNull(Object obj) { if (obj != null) { throw new AssertionError("Passed object: " + obj.getClass().getName() + " is not null while this was expected"); } } }