docs: function request(RequestConstructor, method, url) {
    // callback
    if ('function' == typeof url) {
      return new RequestConstructor('GET', method).end(url);
    }
  
    // url first
    if (2 == arguments.length) {
      return new RequestConstructor('GET', method);
    }
  
    return new RequestConstructor(method, url);
  }