protected function checkOAuthResponse(TransportClientResponse $response) {
        $this->checkHttpStatus($response);

        $body = $response->getBody();
        $decode_body = $this->decodeBody($body);

        if (isset($decode_body[static::RESPONSE_KEY_ERROR])) {
            throw new VKOAuthException("{$decode_body[static::RESPONSE_KEY_ERROR_DESCRIPTION]}. OAuth error {$decode_body[static::RESPONSE_KEY_ERROR]}");
        }

        return $decode_body;
    }