dispose method

Implementation

void dispose() {
  if (_disposed) return;
  _disposed = true;
  _started = false;
  _backgroundTimer?.cancel();
  _typingTimer?.cancel();
  _bootstrapTimer?.cancel();
  _closeSocket();
  unawaited(_states.close());
  unawaited(_events.close());
  unawaited(_openRequests.close());
}