// Constructor for interop-based creation; SetHandle() will be called later
 // Constructor for a track associated with a peer connection.
 internal LocalVideoTrack(PeerConnection peer,
                          Transceiver transceiver, string trackName, ExternalVideoTrackSource source = null) : base(peer, trackName)
 {
     Debug.Assert(transceiver.MediaKind == MediaKind.Video);
     Debug.Assert(transceiver.LocalVideoTrack == null);
     Transceiver = transceiver;
     transceiver.LocalVideoTrack = this;
     Source = source;
     source?.OnTrackAddedToSource(this);
 }
 // Constructor for interop-based creation; SetHandle() will be called later.
 // Constructor for standalone track not associated to a peer connection.
 internal LocalVideoTrack(string trackName, ExternalVideoTrackSource source = null) : base(null, trackName)
 {
     Transceiver = null;
     Source      = source;
     source?.OnTrackAddedToSource(this);
 }