diff --git a/core/lib/Drupal/Core/Condition/ConditionManager.php b/core/lib/Drupal/Core/Condition/ConditionManager.php
index 96cc00e..dfb7a10 100644
--- a/core/lib/Drupal/Core/Condition/ConditionManager.php
+++ b/core/lib/Drupal/Core/Condition/ConditionManager.php
@@ -50,6 +50,14 @@ public function __construct(\Traversable $namespaces, CacheBackendInterface $cac
 
   /**
    * Override of Drupal\Component\Plugin\PluginManagerBase::createInstance().
+   *
+   * @param string $plugin_id
+   *   The ID of the plugin being instantiated.
+   * @param array $configuration
+   *   An array of configuration relevant to the plugin instance.
+   *
+   * @return object
+   *   A fully configured plugin instance.
    */
   public function createInstance($plugin_id, array $configuration = array()) {
     $plugin = $this->getFactory()->createInstance($plugin_id, $configuration);