Java tutorial
//package com.java2s; //License from project: Open Source License import java.util.Arrays; import java.util.Collections; import java.util.HashSet; import java.util.Set; public class Main { /** Shortcut for creating a Set collection. Used for the list of required and unbound parameters. */ public static <T2> Set<T2> unmodifiableSet(T2... items) { return Collections.unmodifiableSet(new HashSet<T2>(Arrays.asList(items))); } }