function createAnimationRemovedFunction(
  modelAnimationCollection,
  model,
  animation,
) {
  return function () {
    modelAnimationCollection.animationRemoved.raiseEvent(model, animation);
  };
}
Returns the animation in the collection at the specified index.  Indices are zero-based
and increase as animations are added.  Removing an animation shifts all animations after
it to the left, changing their indices.  This function is commonly used to iterate over
all the animations in the collection.

@param {number} index The zero-based index of the animation.
@returns {ModelAnimation} The runtime animation at the specified index.

@example
// Output the names of all the animations in the collection.
const animations = model.activeAnimations;
const length = animations.length;
for (let i = 0; i < length; ++i) {
  console.log(animations.get(i).name);
}