add server-side code and mobile app code

server/vendor/symfony/http-client/Chunk/LastChunk.php

@@ -0,0 +1,25 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\HttpClient\Chunk;
+
+/**
+ * @author Nicolas Grekas <p@tchwork.com>
+ *
+ * @internal
+ */
+class LastChunk extends DataChunk
+{
+    public function isLast(): bool
+    {
+        return true;
+    }
+}