observe method

@override Dispose observe(SetChangeListener<T> listener, { bool fireImmediately = false, })

Attaches a listener to changes happening in the ObservableSet. You have the option to be notified immediately (fireImmediately) or wait for until the first change.

Implementation

@override
Dispose observe(
  SetChangeListener<T> listener, {
  bool fireImmediately = false,
}) {
  if (fireImmediately == true) {
    for (final value in _set) {
      listener(
        SetChange(object: this, type: OperationType.add, value: value),
      );
    }
  }
  return _listeners.add(listener);
}