Here you can find the source of addAll(T coll, Collection
public static <E, T extends List<? super E>> T addAll(T coll, Collection<E> other)
//package com.java2s; /******************************************************************************* * Copyright (c) 2007 DSource.org 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:// w ww . ja v a 2 s . c o m * Bruno Medeiros - initial implementation *******************************************************************************/ import java.util.Collection; import java.util.List; public class Main { public static <E, T extends List<? super E>> T addAll(T coll, Collection<E> other) { coll.addAll(other); return coll; } }