public static void Show(UGUIAtlas atlas, UnityAction <Sprite> onClickSprite = null, UnityAction <Sprite> onDoubleClickSprite = null, Sprite currentSprite = null)
 {
     if (instance != null)
     {
         instance.Close();
         instance = null;
     }
     instance                     = ScriptableWizard.DisplayWizard <AtlasSpriteSelector> ("Select a Sprite");
     instance.targetAtlas         = atlas;
     instance.onClickSprite       = onClickSprite;
     instance.onDoubleClickSprite = onDoubleClickSprite;
     instance.currentSprite       = currentSprite;
 }