private function parseResponse(TransportClientResponse $response) {
        $this->checkHttpStatus($response);

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

        if (isset($decode_body[static::KEY_ERROR])) {
            $error = $decode_body[static::KEY_ERROR];
            $api_error = new VKApiError($error);
            throw ExceptionMapper::parse($api_error);
        }

        if (isset($decode_body[static::KEY_RESPONSE])) {
            return $decode_body[static::KEY_RESPONSE];
        } else {
            return $decode_body;
        }
    }