public function setBody($body) : Response
    {
        if (is_null($body) || is_scalar($body)) {
            $this->body = (string) $body;

            return $this;
        }

        $prefix = 'Body must be null or scalar, ';
        $suffix = gettype($body) . ' given.';

        throw new \InvalidArgumentException("{$prefix}{$suffix}");
    }