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

vendor/symfony/validator/Constraints/Traverse.php

@@ -0,0 +1,55 @@
+<?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\Constraints;
+
+use Symfony\Component\Validator\Constraint;
+use Symfony\Component\Validator\Exception\ConstraintDefinitionException;
+
+/**
+ * @Annotation
+ *
+ * @since  2.5
+ *
+ * @author Bernhard Schussek <bschussek@gmail.com>
+ */
+class Traverse extends Constraint
+{
+    public $traverse = true;
+
+    public function __construct($options = null)
+    {
+        if (is_array($options) && array_key_exists('groups', $options)) {
+            throw new ConstraintDefinitionException(sprintf(
+                'The option "groups" is not supported by the constraint %s',
+                __CLASS__
+            ));
+        }
+
+        parent::__construct($options);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getDefaultOption()
+    {
+        return 'traverse';
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getTargets()
+    {
+        return self::CLASS_CONSTRAINT;
+    }
+}