diff --git a/core/modules/views/src/Plugin/views/display/DisplayPluginBase.php b/core/modules/views/src/Plugin/views/display/DisplayPluginBase.php
index 0267879..0eae08b 100644
--- a/core/modules/views/src/Plugin/views/display/DisplayPluginBase.php
+++ b/core/modules/views/src/Plugin/views/display/DisplayPluginBase.php
@@ -76,7 +76,7 @@
    *
    * @var \Drupal\views\Plugin\views\display_extender\DisplayExtenderPluginBase[]
    */
-  protected $extender = [];
+  protected $extenders = [];
 
   /**
    * Overrides Drupal\views\Plugin\Plugin::$usesOptions.
@@ -161,7 +161,7 @@ public function initDisplay(ViewExecutable $view, array &$display, array &$optio
 
     // Load extenders as soon as possible.
     $display['display_options'] += ['display_extenders' => []];
-    $this->extender = array();
+    $this->extenders = array();
     if ($extenders = Views::getEnabledDisplayExtenders()) {
       $manager = Views::pluginManager('display_extender');
       $display_extender_options = $display['display_options']['display_extenders'];
@@ -170,7 +170,7 @@ public function initDisplay(ViewExecutable $view, array &$display, array &$optio
         if ($plugin = $manager->createInstance($extender)) {
           $extender_options = isset($display_extender_options[$plugin->getPluginId()]) ? $display_extender_options[$plugin->getPluginId()] : [];
           $plugin->init($this->view, $this, $extender_options);
-          $this->extender[$extender] = $plugin;
+          $this->extenders[$extender] = $plugin;
         }
       }
     }
@@ -245,7 +245,7 @@ public function destroy() {
       unset($this->default_display);
     }
 
-    foreach ($this->extender as $extender) {
+    foreach ($this->extenders as $extender) {
       $extender->destroy();
     }
   }
@@ -499,7 +499,7 @@ public function defaultableSections($section = NULL) {
       unset($sections['items_per_page']);
     }
 
-    foreach ($this->extender as $extender) {
+    foreach ($this->extenders as $extender) {
       $extender->defaultableSections($sections, $section);
     }
 
@@ -709,14 +709,14 @@ protected function defineOptions() {
       unset($options['defaults']);
     }
 
-    $options['display_extenders'] = ['default' => [], ];
+    $options['display_extenders'] = ['default' => []];
     // First allow display extenders to provide new options.
-    foreach ($this->extender as $extender_id => $extender) {
+    foreach ($this->extenders as $extender_id => $extender) {
       $options['display_extenders']['contains'][$extender_id]['contains'] = $extender->defineOptions();
     }
 
     // Then allow display extenders to alter existing default values.
-    foreach ($this->extender as $extender) {
+    foreach ($this->extenders as $extender) {
       $extender->defineOptionsAlter($options);
     }
 
@@ -1924,7 +1924,7 @@ public function validateOptionsForm(&$form, FormStateInterface $form_state) {
       }
     }
 
-    foreach ($this->extender as $extender) {
+    foreach ($this->extenders as $extender) {
       $extender->validateOptionsForm($form, $form_state);
     }
   }
@@ -2028,7 +2028,7 @@ public function submitOptionsForm(&$form, FormStateInterface $form_state) {
     }
 
     $extender_options = $this->getOption('display_extenders');
-    foreach ($this->extender as $extender) {
+    foreach ($this->extenders as $extender) {
       $extender->submitOptionsForm($form, $form_state);
 
       $plugin_id = $extender->getPluginId();
@@ -2085,7 +2085,7 @@ public function setOverride($section, $new_state = NULL) {
    * Inject anything into the query that the display handler needs.
    */
   public function query() {
-    foreach ($this->extender as $extender) {
+    foreach ($this->extenders as $extender) {
       $extender->query();
     }
   }
@@ -2292,7 +2292,7 @@ public function preExecute() {
       $exposed_form->preExecute();
     }
 
-    foreach ($this->extender as $extender) {
+    foreach ($this->extenders as $extender) {
       $extender->preExecute();
     }
   }
@@ -2667,8 +2667,8 @@ protected function mergeHandler($type) {
    *
    * @return \Drupal\views\Plugin\views\display_extender\DisplayExtenderPluginBase[]
    */
-  public function getExtender() {
-    return $this->extender;
+  public function getExtenders() {
+    return $this->extenders;
   }
 
 }
diff --git a/core/modules/views/src/Tests/Plugin/DisplayExtenderTest.php b/core/modules/views/src/Tests/Plugin/DisplayExtenderTest.php
index b283157..51ce6f5 100644
--- a/core/modules/views/src/Tests/Plugin/DisplayExtenderTest.php
+++ b/core/modules/views/src/Tests/Plugin/DisplayExtenderTest.php
@@ -41,9 +41,9 @@ public function testDisplayExtenders() {
     $view = Views::getView('test_view');
     $view->initDisplay();
 
-    $this->assertEqual(count($view->display_handler->getExtender()), 1, 'Make sure that only one extender is initialized.');
+    $this->assertEqual(count($view->display_handler->getExtenders()), 1, 'Make sure that only one extender is initialized.');
 
-    $display_extender = $view->display_handler->getExtender()['display_extender_test'];
+    $display_extender = $view->display_handler->getExtenders()['display_extender_test'];
     $this->assertTrue($display_extender instanceof \Drupal\views_test_data\Plugin\views\display_extender\DisplayExtenderTest, 'Make sure the right class got initialized.');
 
     $view->preExecute();
diff --git a/core/modules/views_ui/src/Tests/DisplayExtenderUITest.php b/core/modules/views_ui/src/Tests/DisplayExtenderUITest.php
index d5e00fa..30a5c7e 100644
--- a/core/modules/views_ui/src/Tests/DisplayExtenderUITest.php
+++ b/core/modules/views_ui/src/Tests/DisplayExtenderUITest.php
@@ -17,17 +17,6 @@
 class DisplayExtenderUITest extends UITestBase {
 
   /**
-   * Set to TRUE to strict check all configuration saved.
-   *
-   * @see \Drupal\Core\Config\Testing\ConfigSchemaChecker
-   *
-   * @todo https://www.drupal.org/node/2387149
-   *
-   * @var bool
-   */
-  protected $strictConfigSchema = FALSE;
-
-  /**
    * Views used by this test.
    *
    * @var array