Minor change.

Author: AlexanderNikitin

Diff for: src/main/java/an/kte/service/StatisticService.java

@@ -86,7 +86,7 @@ public ClientStatistic findByClientId(Long clientId) {
         return clientStatisticRepository.findByClientId(clientId);
     }
 
-    public ProductStatistic findByProductId(Long clientId) {
-        return productStatisticRepository.findByProductId(clientId);
+    public ProductStatistic findByProductId(Long productId) {
+        return productStatisticRepository.findByProductId(productId);
     }
 }