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

vendor/symfony/serializer/Mapping/AttributeMetadataInterface.php

@@ -0,0 +1,50 @@
+<?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\Serializer\Mapping;
+
+/**
+ * Stores metadata needed for serializing and deserializing attributes.
+ *
+ * Primarily, the metadata stores serialization groups.
+ *
+ * @author Kévin Dunglas <dunglas@gmail.com>
+ */
+interface AttributeMetadataInterface
+{
+    /**
+     * Gets the attribute name.
+     *
+     * @return string
+     */
+    public function getName();
+
+    /**
+     * Adds this attribute to the given group.
+     *
+     * @param string $group
+     */
+    public function addGroup($group);
+
+    /**
+     * Gets groups of this attribute.
+     *
+     * @return string[]
+     */
+    public function getGroups();
+
+    /**
+     * Merges an {@see AttributeMetadataInterface} with in the current one.
+     *
+     * @param AttributeMetadataInterface $attributeMetadata
+     */
+    public function merge(AttributeMetadataInterface $attributeMetadata);
+}