The Mysterious GatherProperties override

GatherPropertiesExample.cs

//[Omitted...]
public class CustomTransformationTrack : TrackAsset
{
        //[Omitted...]
	
        public override void GatherProperties(PlayableDirector director, IPropertyCollector driver)
	{
#if UNITY_EDITOR
		Transform trackBinding = director.GetGenericBinding(this) as Transform;
		if (trackBinding == null)
			return;

		var serializedObject = new UnityEditor.SerializedObject(trackBinding);
		var iterator = serializedObject.GetIterator();
		while (iterator.NextVisible(true))
		{
			if (iterator.hasVisibleChildren)
				continue;

			driver.AddFromName<Transform>(trackBinding.gameObject, iterator.propertyPath);
		}
#endif
		base.GatherProperties(director, driver);
	}
}