code: def get_translation_field_excludes(self, exclude_languages=None):
          
          if exclude_languages is None:
              exclude_languages = []
          excl_languages = []
          if exclude_languages:
              excl_languages = exclude_languages
          exclude = []
          for orig_fieldname, translation_fields in self.trans_opts.fields.items():
              for tfield in translation_fields:
                  if tfield.language in excl_languages and tfield not in exclude:
                      exclude.append(tfield)
          return tuple(exclude)
docs: Returns a tuple of translation field names to exclude based on
          `exclude_languages` arg.
          TODO: Currently unused?