public void Reset()
 {
     NowLayer  = startLayer;
     LastLayer = null;
     for (int i = 0; i < layers.Count; i++)
     {
         var layer = layers[i];
         if (layer == startLayer)
         {
             layer.SwitchToThis(true);
         }
         else
         {
             layer.CloseThis(true);
         }
     }
 }
 public void Register(SmallLayer layer)
 {
     layers.Add(layer);
 }