code: def field(self):
          
          if not self.__field:
              default_field = inflection.underscore(self.__name)
              if isinstance(self, orb.ReferenceColumn):
                  default_field += '_id'
              self.__field = default_field
  
          return self.__field or default_field
docs: Returns the field name that this column will have inside the database.
  
          :return     <str>