public function add($ch)
{
$deferred = new Deferred();
$errno = curl_multi_add_handle($this->mh, $ch);
if ($errno !== CURLM_OK) {
// @codeCoverageIgnoreStart
$msg = curl_multi_strerror($errno) . ": {$ch}";
$deferred->reject(new \RuntimeException($msg));
return $deferred->promise();
// @codeCoverageIgnoreEnd
}
$this->added[(string) $ch] = $ch;
$this->deferreds[(string) $ch] = $deferred;
return $deferred->promise();
}