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

vendor/symfony/validator/Mapping/CascadingStrategy.php

@@ -0,0 +1,54 @@
+<?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\Mapping;
+
+/**
+ * Specifies whether an object should be cascaded.
+ *
+ * Cascading is relevant for any node type but class nodes. If such a node
+ * contains an object of value, and if cascading is enabled, then the node
+ * traverser will try to find class metadata for that object and validate the
+ * object against that metadata.
+ *
+ * If no metadata is found for a cascaded object, and if that object implements
+ * {@link \Traversable}, the node traverser will iterate over the object and
+ * cascade each object or collection contained within, unless iteration is
+ * prohibited by the specified {@link TraversalStrategy}.
+ *
+ * Although the constants currently represent a boolean switch, they are
+ * implemented as bit mask in order to allow future extensions.
+ *
+ * @since  2.5
+ *
+ * @author Bernhard Schussek <bschussek@gmail.com>
+ *
+ * @see TraversalStrategy
+ */
+class CascadingStrategy
+{
+    /**
+     * Specifies that a node should not be cascaded.
+     */
+    const NONE = 1;
+
+    /**
+     * Specifies that a node should be cascaded.
+     */
+    const CASCADE = 2;
+
+    /**
+     * Not instantiable.
+     */
+    private function __construct()
+    {
+    }
+}