/**********************************************

This is a sample test main() for Person. It should output:

false
true
true

and then throw a RuntimeException (see the comments).

*************************************************/

public static void main(String[] args) {

    Person first = new Person("Kim");
    Person second = new Person("Pat");
    
    StdOut.println(first.knows(second));   // should print "false"
    
    first.meet(second);
    
    StdOut.println(first.knows(second));   // should print "true"
    StdOut.println(second.knows(first));   // should print "true"
    
    first.knows(first);                    // should throw a RuntimeException

}