public SpriteAnimationStepWrapper(
     SpriteAnimationAsset asset,
     SpriteAnimationStep step,
     SpriteWrapper spriteWrapper) : this(asset, step)
 {
     this._spriteWrapper = spriteWrapper;
 }
 public SpriteAnimationStepWrapper(SpriteAnimationAsset asset, SpriteAnimationStep step)
 {
     this._asset = asset;
     this.Step   = step;
 }