cancel method

Future<void> cancel()

Implementation

Future<void> cancel() {
  final existing = _cancelling;
  if (existing != null) return existing;
  if (_ended) return Future<void>.value();
  _cancelled = true;
  final completion = Completer<void>();
  _cancelling = completion.future;
  completion.complete(Future<void>.sync(_close!).whenComplete(_finish));
  return completion.future;
}