class Person {
    private String name;    // name of current Person
    private Person friend;  // friend of current Person
                            // is also a Person
    public Person() { }     // constructor
    
    // Set current Person's $name$:
    public void setName(String n) { 
	name = n;
    }

    // Set current Person's $friend$:
    public void setFriend(Person p) { 
	friend = p;
    }

    // Return description of current object:
    public String toString() {
        return "Name: "+name+"; Friend: "+friend.name;
    }
}

public class aggregation {
    public static void main(String[] args) {
        
        // create 2 new people:
	Person a = new Person();
	Person b = new Person();

	// set names of the people:
	a.setName("Ira");
	b.setName("Able");
	
	// make friends:
	a.setFriend(b);
	b.setFriend(a);
	
	// print descriptions:
	System.out.println(a);
	System.out.println(b);
    }
}

/* output:
Name: Ira; Friend: Able
Name: Able; Friend: Ira
*/