add test batches

app/Services/FeeCalculationService.php

@@ -8,12 +8,12 @@ class FeeCalculationService
 {
     public function __construct(
         private FeeRefundCalculatorService $refundCalculator
-    ) {}
+    ) {
+    }
 
     public function calculateRefund(array $students, int $parentId): float
     {
         $result = $this->refundCalculator->calculateRefund($students, $parentId);
-
         return (float) ($result['refund_amount'] ?? 0);
     }
 }