// By Haw-ren Fang, TA of cmsc420 section 0401, Spring 2002

import java.util.*;

// Class PatchSet is an adaptor of HashSet.
// It restricts that the objects in the set must be patchs (see class Patch).

public class PatchSet {
	private HashSet set;

	public PatchSet() {
		set = new HashSet();
	}

	public boolean add(Patch p) {
		return set.add(p);
	}

	public boolean remove(Patch p) {
		return set.remove(p);
	}

	public boolean contains(Patch p) {
		return set.contains(p);
	}

	public Iterator iterator() {
		return set.iterator();
	}
}