feat : Proxy payment

app/Service/Test/Proxy/Payment/PaymentService.php

@@ -0,0 +1,29 @@
+<?php
+/**
+ * This service file is part of item.
+ *
+ * @author   ctexthuang
+ * @contact  ctexthuang@qq.com
+ * @web_site  https://ctexthuang.com
+ */
+
+declare(strict_types=1);
+
+namespace App\Service\Test\Proxy\Payment;
+
+use App\Interface\Test\Proxy\PaymentInterface;
+
+class PaymentService implements PaymentInterface
+{
+    /**
+     * @param float $amount
+     * @return array
+     */
+    public function pay(float $amount): array
+    {
+        return [
+            'amount' => $amount,
+            'msg' => 'Processing payment of '.$amount. PHP_EOL,
+        ];
+    }
+}