添加获取access_token的接口

src/Store/Lib/WeappInterface.php

+<?php
+/**
+ * This file is part of Swoft.
+ *
+ * @link https://swoft.org
+ * @document https://doc.swoft.org
+ * @contact group@swoft.org
+ * @license https://github.com/swoft-cloud/swoft/blob/master/LICENSE
+ */
+
+namespace Hdll\Services\Store\Lib;
+
+use Swoft\Core\ResultInterface;
+
+/**
+ * The interface of store-commission service
+ *
+ * @method ResultInterface deferGetWxAccessToken(int $appId, string $appSecret)
+ */
+interface WeappInterface
+{
+    /**
+     * 根据appId获取对应的access_token
+     * 
+     * @Number(name="appId")
+     * @param int $appId
+     * @param string $appSecret
+     * @return string
+     */
+    public function getWxAccessToken(int $appId, string $appSecret);
+    
+}
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