chore: rename PaymentCounter methods for clarity

Author: otaviojava

src/main/java/com/acme/statistics/PaymentCounter.java

@@ -31,11 +31,11 @@ public class PaymentCounter {
     PaymentCounter() {
     }
 
-    public void failedPayments() {
+    public void paymentFailed() {
         this.failedPayments++;
     }
 
-    public void successfulPayments() {
+    public void paymentSucceeded() {
         this.successfulPayments++;
     }
 }

src/main/java/com/acme/statistics/PaymentCounterService.java

@@ -38,7 +38,7 @@ void success(@Observes PaymentSuccessEvent event) {
         Payment payment = event.payment();
         Product product = payment.getProduct();
         PaymentCounter counter = repository.findById(payment.getProduct().code()).orElseGet(() -> new PaymentCounter(product));
-        counter.successfulPayments();
+        counter.paymentSucceeded();
         repository.save(counter);
     }
 
@@ -48,7 +48,7 @@ void success(@Observes PaymentErrorEvent event) {
         Payment payment = event.payment();
         Product product = payment.getProduct();
         PaymentCounter counter = repository.findById(payment.getProduct().code()).orElseGet(() -> new PaymentCounter(product));
-        counter.failedPayments();
+        counter.paymentFailed();
         repository.save(counter);
     }