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

vendor/symfony/validator/GroupSequenceProviderInterface.php

@@ -0,0 +1,26 @@
+<?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\Validator;
+
+/**
+ * Defines the interface for a group sequence provider.
+ */
+interface GroupSequenceProviderInterface
+{
+    /**
+     * Returns which validation groups should be used for a certain state
+     * of the object.
+     *
+     * @return array An array of validation groups
+     */
+    public function getGroupSequence();
+}