code: def url_is(white_list):
      
      def func(url):
          prefixes = white_list.get('PREFIXES', ())
          for prefix in prefixes:
              if url.startswith(prefix):
                  return True
          constants = white_list.get('CONSTANTS', ())
          for exact_url in constants:
              if url == exact_url:
                  return True
          return False
      return func
docs: Function generator.
  
      Args:
          white_list (dict): dict with PREFIXES and CONSTANTS keys (list values).
  
      Returns:
          func: a function to check if a URL is...