Here you can find the source of assertNotNull(final Object o, final String message)
static void assertNotNull(final Object o, final String message)
//package com.java2s; //License from project: Open Source License public class Main { static void assertNotNull(final Object o, final String message) { if (o == null) throw new NullPointerException(message); }/*from w w w . j a va 2s .c om*/ }