start method

@override Future<void> start()

Start the short poll, throws ShortPollingException on error or a short poll that is already in place

Implementation

@override
Future<void> start() {
  if (!_isPolling) {
    _isPolling = true;
    return _recursivePolling();
  } else {
    throw ShortPollingException('A short poll is already in place');
  }
}