Here you can find the source of assertDifferentInstance(final Object o1, final Object o2)
public static void assertDifferentInstance(final Object o1, final Object o2)
//package com.java2s; //License from project: Open Source License public class Main { public static void assertDifferentInstance(final Object o1, final Object o2) { if (o1 == o2) { throw new AssertionError("The compared objects are the same instance of a class"); }//w w w . j a v a 2 s .c o m } }