anchor.diff:    automatic,
   }
   
  +extension _ApplePayButtonTypeAsset on ApplePayButtonType {
  +  double get minimumAssetWidth => this == ApplePayButtonType.plain ? 100 : 140;
  +}
  +
   class RawApplePayButton extends StatelessWidget {
  +  static const double _minimumButtonHeight = 30;
  +
     final BoxConstraints constraints;
     final EdgeInsets margin;
  -  final VoidCallback onPressed;
  +  final VoidCallback? onPressed;
     final ApplePayButtonStyle style;
     final ApplePayButtonType type;
   
     RawApplePayButton({
       Key? key,
  -    required this.onPressed,
  +    this.onPressed,
       this.margin = EdgeInsets.zero,
       this.style = ApplePayButtonStyle.black,
       this.type = ApplePayButtonType.plain,
  -    double? width,
  -    double? height = _defaultButtonHeight,
  -  })  : constraints = BoxConstraints.tightFor(width: width, height: height),
  +  })  : constraints = BoxConstraints.tightFor(
  +          width: type.minimumAssetWidth,
  +          height: _minimumButtonHeight,
  +        ),
           super(key: key) {
       assert(constraints.debugAssertIsValid());
     }
  
positive.code: 
    _UiKitApplePayButton({
      Key? key,
      required this.onPressed,
      this.style = ApplePayButtonStyle.black,
      this.type = ApplePayButtonType.plain,
    }) : super(key: key);
  
negative.code: part of '../../pay_ios.dart';
  
  enum ApplePayButtonType {
    plain,
  