Drupal 8.0.0 beta 12. More info: https://www.drupal.org/node/2514176

core/lib/Drupal/Component/Annotation/PluginID.php

@@ -0,0 +1,44 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Component\Annotation\PluginID.
+ */
+
+namespace Drupal\Component\Annotation;
+
+/**
+ * Defines a Plugin annotation object that just contains an ID.
+ *
+ * @Annotation
+ */
+class PluginID extends AnnotationBase {
+
+  /**
+   * The plugin ID.
+   *
+   * When an annotation is given no key, 'value' is assumed by Doctrine.
+   *
+   * @var string
+   */
+  public $value;
+
+  /**
+   * {@inheritdoc}
+   */
+  public function get() {
+    return array(
+      'id' => $this->value,
+      'class' => $this->class,
+      'provider' => $this->provider,
+    );
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getId() {
+    return $this->value;
+  }
+
+}