Here you can find the source of addAll(final List
public static <T extends Object> List<T> addAll(final List<T> firstList, final List<T> secondList)
//package com.java2s; /******************************************************************************* * Copyright (c) 2015 Vienna University of Technology. * 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://from ww w . j a v a2s . co m * Martin Fleck (Vienna University of Technology) - initial API and implementation * * Initially developed in the context of ARTIST EU project www.artist-project.eu *******************************************************************************/ import java.util.ArrayList; import java.util.List; public class Main { public static <T extends Object> List<T> addAll(final List<T> firstList, final List<T> secondList) { final List<T> result = new ArrayList<>(firstList); result.addAll(secondList); return result; } }