onOpen<R> method

FutureOr<R> onOpen<R>(FutureOr<R> f())

Implementation

FutureOr<R> onOpen<R>(FutureOr<R> Function() f) {
  if (_open) {
    return f();
  } else {
    return _openCompleter.future.then((_) {
      return f();
    });
  }
}