diff --git a/core/modules/views/src/Plugin/views/display/DisplayPluginBase.php b/core/modules/views/src/Plugin/views/display/DisplayPluginBase.php
index 8b6e83d..0a75ed3 100644
--- a/core/modules/views/src/Plugin/views/display/DisplayPluginBase.php
+++ b/core/modules/views/src/Plugin/views/display/DisplayPluginBase.php
@@ -2641,12 +2641,12 @@ public function getExtenders() {
   }
 
   /**
-   * Returns a specific display extender.
+   * Returns the requested display extender.
    *
    * @param string $id
-   *   The id of the requested extender.
+   *   The ID of the requested display extender.
    *
-   * @return \Drupal\views\Plugin\views\display_extender\DisplayExtenderPluginBase.
+   * @return \Drupal\views\Plugin\views\display_extender\DisplayExtenderPluginBase
    */
   public function getExtender($id) {
     return isset($this->extenders[$id]) ? $this->extenders[$id] : NULL;
diff --git a/core/modules/views/src/Tests/Plugin/DisplayExtenderTest.php b/core/modules/views/src/Tests/Plugin/DisplayExtenderTest.php
index 33c3713..4ccc546 100644
--- a/core/modules/views/src/Tests/Plugin/DisplayExtenderTest.php
+++ b/core/modules/views/src/Tests/Plugin/DisplayExtenderTest.php
@@ -38,8 +38,12 @@ public function testDisplayExtenders() {
 
     $this->assertEqual(count($view->display_handler->getExtenders()), 1, 'Make sure that only one extender is initialized.');
 
+    $display_extender = $view->display_handler->getExtender('display_extender_test_not_initialized');
+    $this->assertEqual($display_extender, NULL, 'Make sure NULL is returned if requested class is not initialized.');
+
     $display_extender = $view->display_handler->getExtenders()['display_extender_test'];
     $this->assertTrue($display_extender instanceof DisplayExtenderTestData, 'Make sure the right class got initialized.');
+    $this->assertTrue($display_extender instanceof DisplayExtenderTestData, 'Make sure the requested class is returned.');
 
     $view->preExecute();
     $this->assertTrue($display_extender->testState['preExecute'], 'Make sure the display extender was able to react on preExecute.');