private function parseBody($response, $httpCode)
    {
        if (!is_string($response)) {
            return;
        }

        $parsed = json_decode($response, 1);
        if (json_last_error() !== 0) {
            throw new MonetivoException('API response is malformed: ' . json_last_error_msg(), 0, $httpCode, $response);
        }

        $this->body = $parsed;
    }