def _check_field_spec(self, obj, model, fields, label):

        if isinstance(fields, tuple):
            return list(chain(*[
                self._check_field_spec_item(obj, model, field_name, "%s[%d]" % (label, index))
                for index, field_name in enumerate(fields)
            ]))
        else:
            return self._check_field_spec_item(obj, model, fields, label)
Generic get_fieldsets code, shared by
dataset/ETHPy150Open django/django/django/contrib/admin/checks.py/BaseModelAdminChecks._check_field_spec--crossover with--dataset/ETHPy150Open deschler/django-modeltranslation/modeltranslation/admin.py/TranslationBaseModelAdmin._get_fieldsets_post_form_or_formset