anchor.diff:              ),
             ),
             SizedBox(height: 15),
  -          Center(child: _getPaymentButtons())
  -        ]));
  +          Center(
  +            child: SizedBox(
  +              width: double.infinity,
  +              child: GooglePayButtonWidget(
  +                paymentConfigurationAsset: 'default_payment_profile.json',
  +                color: GooglePayButtonColor.flat,
  +                type: GooglePayButtonType.pay,
  +                onPressed: googlePayButtonPressed,
  +                childOnError: Text('Google Pay is not available.'),
  +                loadingIndicator: CircularProgressIndicator(),
  +              ),
  +            ),
  +          ),
  +          SizedBox(height: 15),
  +        ],
  +      ),
  +    );
     }
   }
  
positive.code: }
  
  class _PaySampleAppState extends State<PaySampleApp> {
    void googlePayButtonPressed() async {
      var result = await _googlePayClient.showPaymentSelector(price: '99.99');
      debugPrint(result.toString());
    }
  
    Widget _getPaymentButtons() {
      return FutureBuilder<bool>(
        future: _googlePayClient.userCanPay(),
        builder: (context, snapshot) {
          if (snapshot.connectionState == ConnectionState.done) {
            if (snapshot.data == true) {
              return SizedBox(
                  width: double.infinity,
                  child: GooglePayButton(
                      color: GooglePayButtonColor.flat,
                      type: GooglePayButtonType.pay,
                      onPressed: googlePayButtonPressed));
            } else if (snapshot.hasError) {
              PlatformException exc = snapshot.error;
              return Text(exc.message);
            }
          }
  
          return CircularProgressIndicator();
        },
      );
    }
  
    @override
  
negative.code: import 'package:flutter/material.dart';
  import 'package:pay/pay.dart';
  
  void main() {
    runApp(PayMaterialApp());
  