room method
Returns a stream of changes in a room from Firebase.
Implementation
Stream<types.Room> room(String roomId) {
final fu = firebaseUser;
if (fu == null) return const Stream.empty();
return getFirebaseFirestore()
.collection(config.roomsCollectionName)
.doc(roomId)
.snapshots()
.asyncMap(
(doc) => processRoomDocument(
doc,
fu,
getFirebaseFirestore(),
config.usersCollectionName,
),
);
}