new_contents: from itertools import chain
  
  
  # https://docs.djangoproject.com/en/1.10/ref/models/meta/
  def get_all_field_names(model_class):
      field_names = list(set(chain.from_iterable(
          (field.name, field.attname) if hasattr(field, 'attname') else (field.name,)
          for field in model_class._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)
      )))
      return field_names
  
subject: add get_all_field_names on test_utils/