observe method

@override Dispose observe(MapChangeListener<K, V> listener, { bool fireImmediately = false, })

Used to attach a listener for getting notified on changes happening to the map

You can also choose to receive the notifications immediately (with fireImmediately)

Implementation

@override
Dispose observe(
  MapChangeListener<K, V> listener, {
  bool fireImmediately = false,
}) {
  if (fireImmediately == true) {
    _map.forEach((key, value) {
      listener(
        MapChange<K, V>(
          type: OperationType.add,
          key: key,
          newValue: value,
          object: this,
        ),
      );
    });
  }
  return _listeners.add(listener);
}