onInvalidated static method
Listens for invalidation events broadcast on a specific query key.
Returns a broadcast Stream. Callers must call releaseListener on teardown.
Implementation
static Stream<void> onInvalidated(List<dynamic> key) {
final keyStr = normalizeKey(key);
_listenerCounts[keyStr] = (_listenerCounts[keyStr] ?? 0) + 1;
return _invalidationControllers
.putIfAbsent(keyStr, () => StreamController<void>.broadcast())
.stream;
}