package com.sun.source.util; import com.sun.source.io.Serializable; public class HashSet extends AbstractSet implements Set,Serializable,Cloneable { @Override public T[] toArray(T[] a) { // TODO Auto-generated method stub return null; } @Override public boolean retainAll(Collection> c) { // TODO Auto-generated method stub return false; } @Override public Iterator iterator() { // TODO Auto-generated method stub return null; } @Override public int size() { // TODO Auto-generated method stub return 0; } }