multiTransform method
Transform the given refs
to a List of T
s.
The Stream will emmit new values each time there is a change
in the DB.
Implementation
Stream<List<T>> multiTransform({
required Iterable<DocumentReference> refs,
}) {
return CombineLatestStream.list(refs.map<Stream<T>>(
(ref) => transform(ref: ref),
));
}