Java tutorial
//package com.java2s; // This source code is available under the terms of the Affero General Public License v3. import java.util.ArrayList; import java.util.HashSet; import java.util.List; import java.util.Set; public class Main { public static <T> List<T> copy(List<? extends T> a) { return new ArrayList<T>(a); } public static <T> Set<T> copy(Set<? extends T> a) { return new HashSet<T>(a); } }