public SpriteAnimation SetCurrentAnimation(SpriteAnimation animation)
 {
     Verify.That(animation).Named("animation").IsNotNull();
     return _currentAnimation = animation;
 }
 public AnimatedSprite AddAnimation(SpriteAnimation animation)
 {
     Verify.That(animation).Named("animation").IsNotNull();
     _animations.Add(animation);
     return this;
 }