docs: def _get_all_field_names(model):
      """
      100% compatible version of the old API of model._meta.get_all_field_names()
      From: https://docs.djangoproject.com/en/1.9/ref/models/meta/#migrating-from-the-old-api
      """
      return list(set(chain.from_iterable(
          (field.name, field.attname) if hasattr(field, 'attname') else (field.name,)
          for field in model._meta.get_fields()
          # For complete backwards compatibility, you may want to exclude
          # GenericForeignKey from the results.
          if not (field.many_to_one and field.related_model is None)
      )))