public final class Singleton {
    private static Singleton instance;

    private Singleton() {}

    public static Singleton getInstance() {
        if(instance == null)  {
           instance = new Singleton(); 
        }
        return instance;
    }
}

class Hoved {
    public static void main(String[] args) {
        Singleton single = Singleton.getInstance();
        Singleton single2 = Singleton.getInstance();
    }
}