BlueBreeze

class Singleton
{
    private static final Singleton instance = new Singleton();
     
    private Singleton()
    {
        throw new AssertionError();
    }

    public static Singleton getInstance()
    {
        return instance;
    }
    
    public void show()
    {
        System.out.println("Singleton instance showing...");
    }
}

public enum SINGLETON
{
    INSTANCE;

    public void show()
    {
        System.out.println("Singleton instance showing...");
    }
}