public function updateSignatureRequest($request_id, $signature_id, $email)
    {
        $response = $this->rest->post(
            static::SIGNATURE_REQUEST_UPDATE_PATH . '/' . $request_id,
            array('signature_id' => $signature_id, 'email_address' => $email)
        );

        $this->checkResponse($response);

        return new SignatureRequest($response);
    }