A new method 'isError' has been introduced to the ServiceResult interface and its implementation. This change was made to improve readability and logic. Now instead of checking if the result is not successful, we can directly check if it's an error using isError method. This improves the code clarity.

app/Contracts/ServiceResult.php

@@ -6,4 +6,5 @@ namespace App\Contracts;
 interface ServiceResult
 {
     public function isSuccess(): bool;
+    public function isError(): bool;
 }