HttpClient::sendAsyncRequest

public function sendAsyncRequest(RequestInterface $request): PromiseInterface
{
	if (!$this->checkRequest($request))
	{
		throw new HttpRequestException($request, reset($this->error));
	}

	$this->request = $this->buildRequest($request);

	if ($this->queue === null)
	{
		$this->queue = $this->createQueue();
	}

	$promise = $this->createPromise($this->request, $this->queue);

	$this->queue->add($promise);

	return $promise;
}