In MediaBrowserService.onLoadChildren, when/how is the options bundle supplied?

Question

In MediaServiceBrowser or MediaServiceBrowserCompat, there are two methods:

public abstract void onLoadChildren (String parentId, Result<List<MediaBrowser.MediaItem>> result)

and

public void onLoadChildren (String parentId, Result<List<MediaBrowser.MediaItem>> result, Bundle options)

options is described as:

Bundle: The bundle of service-specific arguments sent from the media browser. The information returned through the result should be affected by the contents of this bundle. This value must never be null.

I hoped that providing extras into the MediaDescriptionCompat of the MediaItem (the one whose children are being loaded) would surface them in the second call.

However, only the first method is called, as tested under Android Auto.

What do I need to do to get called with an options argument?