public static function documentsTracking()
{
$refs = array('20400000310076', '20400000310077');
$data = new \NovaPoshta\MethodParameters\InternetDocument_documentsTracking();
$data->setDocuments($refs);
// или
$data->addDocument('20400000310076');
$data->addDocument('20400000310077');
return InternetDocument::documentsTracking($data);
}
