Java Puzzle 2: Dreams (solution)

package dream;

import sleep.Sleeper;

public class Dream {

    public void dream(final Sleeper s) {
        Thread thread = new Thread(new Runnable() {
            public void run() {
                s.enter(new Dream() {
                    @Override
                    public void dream(Sleeper s) {
                        try {
                            s.wait(500);
                        } catch (InterruptedException e) {
                        }
                    }
                });
            }
        });
        thread.start();
        try {
            s.wait(100);
        } catch (InterruptedException e) {
        }
    }

}