docs: def fill_with_model(self, model, *fields):
          """
          Populates this form with localized properties from model.
          :param fields: string list indicating the fields to include. If None, all fields defined on form will be used
          :param model: model
          :return: dict with localized properties
          """
          model_dct = model.to_dict(include=self._fields.keys())
          localized_dct = self.localize(*fields, **model_dct)
          if model.key:
              localized_dct['id'] = model.key.id()
          return localized_dct