resume method

@override void resume()

Resumes polling after pause.

Implementation

@override
void resume() {
  assert(!_disposed, 'Poller#$debugLabel was disposed.');
  if (!_alive) {
    throw StateError('Poller#$debugLabel is not started to be resumed.');
  }
  if (_pauseControl case _PauseControl(:final confirmation, :final pause)) {
    if (!confirmation.isCompleted) confirmation.complete();
    assert(!pause.isCompleted);
    pause.complete();
    _pauseControl = null;
  }
}