import java.util.*;
import java.io.*;


public class Organization implements Serializable {
    private Set<Member> members = new HashSet<Member>();
    public void add(Member m) {
        members.add(m);
    }
    public void remove(Member m) {
        members.remove(m);
    }
    public boolean contains(Member m) {
        return members.contains(m);
    }
    public Iterator<Member> iterator() {
        return members.iterator();
    }
    public int size() {
        return members.size();
    }

    public Member search(String id) {
		for(Member m: members) {
			if (m.getId().equals(id)) {
				return m;
			}
		}
		return null;
	}

    public String toString() {
		String result = "members:\n";
		for(Member m: members) {
			result = result + m + "\n";
		}
		return result;
	}

}