Example 8.33 	ProjectImpl Class
// ProjectImpl.java

package com.corej2eepatterns.business.impl;

import com.corej2eepatterns.business.hr.Project;

import java.util.Collections;
import java.util.HashSet;
import java.util.Set;

public class ProjectImpl implements Project {
	String name;
	Set employees = new HashSet();

	/** Creates a new instance of ProjectImpl */
	ProjectImpl(String name) {
		this.name = name;
	}

	public Set getEmployees() {
		return Collections.unmodifiableSet(employees);
	}

	public String getName() {
		return name;
	}

	boolean addEmployee(EmployeeImpl employee) {
		return employees.add(employee);
	}

	boolean removeEmployee(EmployeeImpl employee) {
		return employees.remove(employee);
	}
}