read method
Reads a notifier and sets up automatic listener tracking.
Implementation
void read(Listenable updaters) {
final data = _notifyData;
final listener = data?.updater;
if (listener != null && !data!._subscribedNotifiers.contains(updaters)) {
data._subscribedNotifiers.add(updaters);
updaters.addListener(listener);
add(() => updaters.removeListener(listener));
}
}