https://lists.w3.org/Archives/Public/public-webrtc/2016Sep/0014.html
[webrtc-pc] pc.createOffer(); pc.addTrack(track); should not include track from jan-ivar via GitHub...
https://developer.mozilla.org/en-US/docs/Web/API/RTCPeerConnection/addTrack
RTCPeerConnection: addTrack() method - Web APIs | MDN
The addTrack() method of the RTCPeerConnection interface adds a new media track to the set of tracks which will be transmitted to the other peer.
web apisrtcpeerconnectionmethodmdn
https://bugzilla.mozilla.org/show_bug.cgi?id=1103188
1103188 - Implement MediaStream.addTrack()/removeTrack()
RESOLVED (apehrson) in Core - Audio/Video: MediaStreamGraph. Last updated 2019-03-31.
implementmediastream