code: def _normalize_options(options):
      
      normalized_options = {}
      for key, value in iteritems(options):
          optname = str(key).lower()
          intname = INTERNAL_URI_OPTION_NAME_MAP.get(optname, key)
          normalized_options[intname] = options[key]
      return normalized_options
docs: Renames keys in the options dictionary to their internally-used
      names.