code: def reload(self, database):
          
          if self.id is None:
              raise ValueError("_id/id property is None")
          self.import_data(database.get(self.id))
          return self
docs: This function reloads/rehydrates the Document Model.  This
          is especially useful for embedded documents that are stored
          in a dehydrated state.
  
          :param database: the `Database` object source for reloading the document
          :return: an updated instance of `Document` / self.