Update to drupal 8.0.0-rc1. For more information, see https://www.drupal.org/node/2582663

vendor/symfony/http-foundation/Session/Storage/Handler/NullSessionHandler.php

@@ -0,0 +1,72 @@
+<?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\HttpFoundation\Session\Storage\Handler;
+
+/**
+ * NullSessionHandler.
+ *
+ * Can be used in unit testing or in a situations where persisted sessions are not desired.
+ *
+ * @author Drak <drak@zikula.org>
+ *
+ * @api
+ */
+class NullSessionHandler implements \SessionHandlerInterface
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function open($savePath, $sessionName)
+    {
+        return true;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function close()
+    {
+        return true;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function read($sessionId)
+    {
+        return '';
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function write($sessionId, $data)
+    {
+        return true;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function destroy($sessionId)
+    {
+        return true;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function gc($maxlifetime)
+    {
+        return true;
+    }
+}