Initial commit，修正

vendor/yiisoft/yii2/helpers/Json.php

@@ -0,0 +1,19 @@
+<?php
+/**
+ * @link https://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license https://www.yiiframework.com/license/
+ */
+
+namespace yii\helpers;
+
+/**
+ * Json is a helper class providing JSON data encoding and decoding.
+ * It enhances the PHP built-in functions `json_encode()` and `json_decode()`
+ * by supporting encoding JavaScript expressions and throwing exceptions when decoding fails.
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @since 2.0
+ */
+class Json extends BaseJson
+{
+}