/// <summary>
        /// CREATIONAL
        /// </summary>
        public void CreateSingleton()
        {
            var instance    = SingletonClass.getInstance();
            var instanceNew = SingletonClass.getInstance();

            Console.WriteLine("{0}; {1}", instance.GetHashCode(), instanceNew.GetHashCode());
            //SingletonClass singletonClass = new SingletonClass(); --> inaccessible
        }