Java tutorial
//package com.java2s; import java.util.Collection; import java.util.Comparator; import java.util.SortedSet; import java.util.concurrent.ConcurrentSkipListSet; public class Main { public static <E> ConcurrentSkipListSet<E> createConcurrentSkipListSet() { return new ConcurrentSkipListSet<E>(); } public static <E> ConcurrentSkipListSet<E> createConcurrentSkipListSet(Collection<? extends E> collection) { if (collection == null) { return new ConcurrentSkipListSet<E>(); } return new ConcurrentSkipListSet<E>(collection); } public static <E> ConcurrentSkipListSet<E> createConcurrentSkipListSet(Comparator<? super E> comparator) { if (comparator == null) { return new ConcurrentSkipListSet<E>(); } return new ConcurrentSkipListSet<E>(comparator); } public static <E> ConcurrentSkipListSet<E> createConcurrentSkipListSet(SortedSet<E> set) { if (set == null) { return new ConcurrentSkipListSet<E>(); } return new ConcurrentSkipListSet<E>(set); } }