getHandler(message) {
    // Do not use WHATWG API yet, stick with the legacy (and deprecated) URL
    // There are two issues:
    //   - Heavy performance impact: https://github.com/nodejs/node/issues/30334
    //   - Double slash bug: https://github.com/nodejs/node/issues/30776
    const parsed = URL.parse(message.url, true);
    let pathname = parsed.pathname || ""; // pathname is set to null if empty

    if (pathname[pathname.length - 1] === "/") {
      pathname = pathname.slice(0, -1);
    }

    const routeHandler = new RouteHandler(pathname, parsed.query, message);

    return getHandlerPart(this, pathname.split("/"), routeHandler);
  }
Returns a RouteHandler instance corresponding to the provided URL
Returns null if no handler was found

@param {HttpMessage} message
@returns {RouteHandler} registered function handler