PaymentItem constructor
      const
      PaymentItem({ 
    
- required String amount,
- required String label,
- PaymentItemType type = PaymentItemType.total,
- PaymentItemStatus status = PaymentItemStatus.unknown,
Creates a new payment item with the specified parameters, defaulting to
a total type, and an unknown status.
Implementation
const PaymentItem({
  required this.amount,
  required this.label,
  this.type = PaymentItemType.total,
  this.status = PaymentItemStatus.unknown,
});