function addAnimation(collection, animation, options) {
  const model = collection._model;
  const runtimeAnimation = new ModelAnimation(model, animation, options);
  collection._runtimeAnimations.push(runtimeAnimation);
  collection.animationAdded.raiseEvent(model, runtimeAnimation);
  return runtimeAnimation;
}
The model that owns this animation collection.

@memberof ModelAnimationCollection.prototype

@type {Model}
@readonly