call method
Implementation
MediaConnection call(String peerId, MediaStream stream) {
if (peerId == id) {
throw Exception('Cannot connect to self.');
}
final connectionId = _uuid.v4();
final connection = MediaConnection(
peerId: peerId,
signalingClient: _signaling,
adapter: _adapter,
connectionId: connectionId,
localStream: stream,
config: _config,
);
_connections[connectionId] = connection;
connection.call();
return connection;
}