Supported actions.
OptionalcontextOptional context.
Live source flag.
Metadata (merged by media.session.update).
Playback owner.
OptionalplaylistPlaylist index when the source url is a seeded track.
Canonical session id.
OptionalsourceSource reference (shell-owned sessions).
Latest playback state.
OptionaltorrentBound torrent job id for torrent sources.
Owning window.
One live media session.