code: def base(self, *paths, **query_kwargs):
          
          kwargs = self._normalize_params(*paths, **query_kwargs)
          if self.path:
              if "path" in kwargs:
                  paths = self.normalize_paths(self.path, kwargs["path"])
                  kwargs["path"] = "/".join(paths)
              else:
                  kwargs["path"] = self.path
          return self.create(self.root, **kwargs)
docs: create a new url object using the current base path as a base
  
          if you had requested /foo/bar, then this would append *paths and **query_kwargs
          to /foo/bar
  
          :example:
              # current path: /foo/bar
  
              print url # http://host.com/foo/bar
  
              print url.base() # http://host.com/foo/bar
              print url.base("che", boom="bam") # http://host/foo/bar/che?boom=bam
  
          :param *paths: list, the paths to append to the current path without query params
          :param **query_kwargs: dict, any query string params to add