Java: Singleton - Lazy Loaded

Singleton that is lazy loaded.

public class Singleton {
    // Private constructor prevents instantiation from other classes
    private Singleton() {}
    
    /**
     * SingletonHolder is loaded on the first execution of Singleton.getInstance() 
     * or the first access to SingletonHolder.INSTANCE, not before.
     */
    private static class SingletonHolder { 
        private static final Singleton INSTANCE = new Singleton();
    }
    
    public static Singleton getInstance() {
        return SingletonHolder.INSTANCE;
    }
}