code: def delete_field_value(self, name):
          
          name = self.get_real_name(name)
  
          if name and self._can_write_field(name):
              if name in self.__modified_data__:
                  self.__modified_data__.pop(name)
  
              if name in self.__original_data__ and name not in self.__deleted_fields__:
                  self.__deleted_fields__.append(name)
docs: Mark this field to be deleted