/**
* add new task and return a promise
*
* @param Task $task
* @param null $task_name
* @return \React\Promise\PromiseInterface
*/
public function attach(Task $task, $task_name = null)
{
if (is_null($task_name)) {
$task_name = count($this->tasks);
}
$this->tasks[$task_name] = $task;
curl_multi_add_handle($this->curl, $task->createCurl());
$deferred = new Deferred();
$this->deferred[$task_name] = $deferred;
return $deferred->promise();
}
