It is accessed by at least two threads:

* `[shutoff]` in `UnregisterHTTPHandler`
* `[http]` in `http_request_cb`
{
    return evhttp_request_get_uri(req);
}
HTTPRequest::RequestMethod HTTPRequest::GetRequestMethod() const
{
    switch (evhttp_request_get_command(req)) {
    case EVHTTP_REQ_GET:
        return GET;
        break;
    case EVHTTP_REQ_POST:
        return POST;
        break;
    case EVHTTP_REQ_HEAD:
        return HEAD;
        break;
    case EVHTTP_REQ_PUT:
        return PUT;
        break;
    default:
        return UNKNOWN;
        break;
    }
}
std::optional<std::string> HTTPRequest::GetQueryParameter(const std::string& key) const