diff -u b/core/lib/Drupal/Core/Menu/MenuTreeStorage.php b/core/lib/Drupal/Core/Menu/MenuTreeStorage.php
--- b/core/lib/Drupal/Core/Menu/MenuTreeStorage.php
+++ b/core/lib/Drupal/Core/Menu/MenuTreeStorage.php
@@ -76,12 +76,12 @@
   /**
    * List of plugin definition fields.
    *
+   * @var array
+   *
    * @todo Decide how to keep these field definitions in sync.
    *   https://www.drupal.org/node/2302085
    *
    * @see \Drupal\Core\Menu\MenuLinkManager::$defaults
-   *
-   * @var array
    */
   protected $definitionFields = [
     'menu_name',
@@ -530,7 +530,7 @@
    * @param array $original
    *   The original menu link.
    */
-  protected function moveChildren($fields, $original) {
+  protected function moveChildren(array $fields, array $original) {
     $query = $this->connection->update($this->table, $this->options);
 
     $query->fields(['menu_name' => $fields['menu_name']]);
@@ -581,7 +581,7 @@
    * @return array|false
    *   Returns a definition array, or FALSE if no parent was found.
    */
-  protected function findParent($link, $original) {
+  protected function findParent(array $link, array $original) {
     $parent = FALSE;
 
     // This item is explicitly top-level, skip the rest of the parenting.
@@ -792,7 +792,9 @@
     // @todo Consider making this dynamic based on static::MAX_DEPTH or from the
     //   schema if that is generated using static::MAX_DEPTH.
     //   https://www.drupal.org/node/2302043
-    $subquery->fields($this->table, ['p1', 'p2', 'p3', 'p4', 'p5', 'p6', 'p7', 'p8', 'p9']);
+    $subquery->fields($this->table, [
+      'p1', 'p2', 'p3', 'p4', 'p5', 'p6', 'p7', 'p8', 'p9',
+    ]);
     $subquery->condition('id', $id);
     $result = current($subquery->execute()->fetchAll(\PDO::FETCH_ASSOC));
     $ids = array_filter($result);
@@ -839,7 +841,7 @@
    * @param array $links
    *   An array of all definitions keyed by ID.
    */
-  protected function saveRecursive($id, &$children, &$links) {
+  protected function saveRecursive($id, array &$children, array &$links) {
     if (!empty($links[$id]['parent']) && empty($links[$links[$id]['parent']])) {
       // Invalid parent ID, so remove it.
       $links[$id]['parent'] = '';
diff -u b/core/modules/menu_link_content/tests/src/Kernel/MenuLinksTest.php b/core/modules/menu_link_content/tests/src/Kernel/MenuLinksTest.php
--- b/core/modules/menu_link_content/tests/src/Kernel/MenuLinksTest.php
+++ b/core/modules/menu_link_content/tests/src/Kernel/MenuLinksTest.php
@@ -69,7 +69,7 @@
     //   - child-1
     //     - child-1-1
     //     - child-1-2
-    //   - child-2
+    //   - child-2.
     $base_options = [
       'title' => 'Menu link test',
       'provider' => $module,
@@ -129,7 +129,11 @@
       $menu_link_plugin = $this->menuLinkManager->createInstance($links[$id]);
       $expected_parent = $links[$parent] ?? '';
 
-      $this->assertEquals($expected_parent, $menu_link_plugin->getParent(), new FormattableMarkup('Menu link %id has parent of %parent, expected %expected_parent.', ['%id' => $id, '%parent' => $menu_link_plugin->getParent(), '%expected_parent' => $expected_parent]));
+      $this->assertEquals($expected_parent, $menu_link_plugin->getParent(), new FormattableMarkup('Menu link %id has parent of %parent, expected %expected_parent.', [
+        '%id' => $id,
+        '%parent' => $menu_link_plugin->getParent(),
+        '%expected_parent' => $expected_parent,
+      ]));
     }
   }
 
@@ -146,7 +150,7 @@
     $link = MenuLinkContent::create($options);
     $link->save();
     // Make sure the changed timestamp is set.
-    $this->assertEquals(REQUEST_TIME, $link->getChangedTime(), 'Creating a menu link sets the "changed" timestamp.');
+    $this->assertEquals(\Drupal::time()->getRequestTime(), $link->getChangedTime(), 'Creating a menu link sets the "changed" timestamp.');
     $options = [
       'title' => 'Test Link',
     ];
@@ -154,7 +158,7 @@
     $link->changed->value = 0;
     $link->save();
     // Make sure the changed timestamp is updated.
-    $this->assertEquals(REQUEST_TIME, $link->getChangedTime(), 'Changing a menu link sets "changed" timestamp.');
+    $this->assertEquals(\Drupal::time()->getRequestTime(), $link->getChangedTime(), 'Changing a menu link sets "changed" timestamp.');
   }
 
   /**