query($query)->then( * function (React\Dns\Model\Message $response) { * // response message successfully received * var_dump($response->rcode, $response->answers); * }, * function (Exception $error) { * // failed to query due to $error * } * ); * ``` * * The returned Promise MUST be implemented in such a way that it can be * cancelled when it is still pending. Cancelling a pending promise MUST * reject its value with an Exception. It SHOULD clean up any underlying * resources and references as applicable. * * ```php * $promise = $executor->query($query); * * $promise->cancel(); * ``` * * @param Query $query * @return \React\Promise\PromiseInterface<\React\Dns\Model\Message> * resolves with response message on success or rejects with an Exception on error */ public function query(Query $query); }