public IndexedAnimationSelector(SPAnimationController controller, SelectorIndexStyle indexStyle, int layer = 0)
 {
     _controller = controller;
     _indexStyle = indexStyle;
     _layer      = layer;
 }
 public IndexedAnimationSelector(SPAnimationController controller, int layer = 0)
 {
     _controller = controller;
     _indexStyle = SelectorIndexStyle.Clamp;
     _layer      = layer;
 }