@property
def is_discount(self) -> bool:
    return ((not self.is_entire_order) and (not self.is_billing_to_credit_card) and (not self.is_shipping_handling) and (self.total_order is not None) and (self.total_order < 0))
@property
def is_discount(self) -> bool:
    return ((not self.is_entire_order) and (not self.is_billing_to_credit_card) and (not self.is_shipping_handling) and (self.total_order is not None) and (self.total_order < 0))