anchor.diff:  
     _UiKitApplePayButton({
       Key? key,
  -    required this.onPressed,
  +    this.onPressed,
       this.style = ApplePayButtonStyle.black,
       this.type = ApplePayButtonType.plain,
     }) : super(key: key);
  
positive.code:   automatic,
  }
  
  class RawApplePayButton extends StatelessWidget {
    final BoxConstraints constraints;
    final EdgeInsets margin;
    final VoidCallback onPressed;
    final ApplePayButtonStyle style;
    final ApplePayButtonType type;
  
    RawApplePayButton({
      Key? key,
      required 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),
          super(key: key) {
      assert(constraints.debugAssertIsValid());
    }
  
negative.code: part of '../../pay_ios.dart';
  
  enum ApplePayButtonType {
    plain,
  