(self)
return None
If this returns None then the unit base_description and base_cost
        will not show up for the line item in the printed invoice.
If this returns None then the unit base_description and base_cost
        will not show up for the line item in the printed invoice.
If this returns None then the unit base_description and base_cost will not show up for the line item in the printed invoice .
def base_description(self):
        """
        If this returns None then the unit base_description and base_cost
        will not show up for the line item in the printed invoice.
        """
        return None
def base_description ( self ) : return None