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

vendor/symfony/serializer/Annotation/Groups.php

@@ -0,0 +1,64 @@
+<?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\Annotation;
+
+use Symfony\Component\Serializer\Exception\InvalidArgumentException;
+
+/**
+ * Annotation class for @Groups().
+ *
+ * @Annotation
+ * @Target({"PROPERTY", "METHOD"})
+ *
+ * @author Kévin Dunglas <dunglas@gmail.com>
+ */
+class Groups
+{
+    /**
+     * @var array
+     */
+    private $groups;
+
+    /**
+     * @param array $data
+     *
+     * @throws InvalidArgumentException
+     */
+    public function __construct(array $data)
+    {
+        if (!isset($data['value']) || !$data['value']) {
+            throw new InvalidArgumentException(sprintf('Parameter of annotation "%s" cannot be empty.', get_class($this)));
+        }
+
+        if (!is_array($data['value'])) {
+            throw new InvalidArgumentException(sprintf('Parameter of annotation "%s" must be an array of strings.', get_class($this)));
+        }
+
+        foreach ($data['value'] as $group) {
+            if (!is_string($group)) {
+                throw new InvalidArgumentException(sprintf('Parameter of annotation "%s" must be an array of strings.', get_class($this)));
+            }
+        }
+
+        $this->groups = $data['value'];
+    }
+
+    /**
+     * Gets groups.
+     *
+     * @return array
+     */
+    public function getGroups()
+    {
+        return $this->groups;
+    }
+}