import java.util.Random;

/*
  This class was copied in its entirety from the book "Object Oriented Design 
  and Patterns" by Cay Horstmann. Only some variable names were changed and
  a output messages were added to help trace the output.
 */

public class SingleRandom
{
    private Random generator;
    private static SingleRandom instance = new SingleRandom ();

    private SingleRandom () 
    { 
	System.out.println(">>> Trace only: this.SingleRandom() <<<");
	generator = new Random (); 
    } 
    
    public void setSeed (int seed) 
    {
	System.out.println(">>> Trace only: ref.setSeed() <<<");
	generator.setSeed(seed);
    }
    
    public int nextInt ()
    {
	System.out.println(">>> Trace only: ref.nextInt() <<<");
	return (generator.nextInt());
    }

    public static SingleRandom getInstance () 
    {
	System.out.println(">>> Trace only: SingleRandom.getInstance() <<<");
	return instance;
    }
}