protected override void Dispose(bool disposing)
        {
            base.Dispose(disposing);

            sprites = null;

            // don't forget to destroy persistent substate
            persistentSubState.Dispose();
            persistentSubState = null;
        }
        protected override void Create()
        {
            FlxG.Cameras.BgColor = Color.White;

            DestroySubStates = false;

            // Some test group of sprites, used for showing substate system features
            sprites = new MySpriteGroup(50);
            Add(sprites);

            subStateColor = new Color(128, 128, 128, 153);

            // We can create persistent substate and use it as many times as we want
            persistentSubState = new SubState(subStateColor);
            persistentSubState.isPersistent = true;

            openpersistentBtn = new FlxButton(20, 20, "OpenPersistent", OnpersistentClick);
            Add(openpersistentBtn);

            openTempBtn = new FlxButton(20, 60, "OpenTemp", OnTempClick);
            Add(openTempBtn);
            base.Create();
        }