dispose method
Disposes the StreamControllers associated with this connection.
Implementation
void dispose() {
  if (_disposed) {
    return;
  }
  _addonController.close();
  _disposed = true;
}
Disposes the StreamControllers associated with this connection.
void dispose() {
  if (_disposed) {
    return;
  }
  _addonController.close();
  _disposed = true;
}