code: def _searchable_form(self) -> 'Language':
          
          if self._searchable is not None:
              return self._searchable
  
          self._searchable = self._filter_attributes(
              {'language', 'script', 'region'}
          ).simplify_script().prefer_macrolanguage()
          return self._searchable
docs: Convert a parsed language tag so that the information it contains is in
          the best form for looking up information in the CLDR.