diff --git a/core/modules/migrate_drupal/tests/src/Kernel/d6/MigrateDrupal6AuditIdsTest.php b/core/modules/migrate_drupal/tests/src/Kernel/d6/MigrateDrupal6AuditIdsTest.php
index a0bb591..860f576 100644
--- a/core/modules/migrate_drupal/tests/src/Kernel/d6/MigrateDrupal6AuditIdsTest.php
+++ b/core/modules/migrate_drupal/tests/src/Kernel/d6/MigrateDrupal6AuditIdsTest.php
@@ -37,6 +37,7 @@ protected function setUp() {
     $this->installSchema('forum', ['forum_index']);
     $this->installSchema('node', ['node_access']);
     $this->installSchema('search', ['search_dataset']);
+    $this->installSchema('system', ['sequences']);
     $this->installSchema('tracker', ['tracker_node', 'tracker_user']);
 
     // Enable content moderation for nodes of type page.
diff --git a/core/modules/migrate_drupal/tests/src/Kernel/d7/MigrateDrupal7AuditIdsTest.php b/core/modules/migrate_drupal/tests/src/Kernel/d7/MigrateDrupal7AuditIdsTest.php
index 1d74423..351ab43 100644
--- a/core/modules/migrate_drupal/tests/src/Kernel/d7/MigrateDrupal7AuditIdsTest.php
+++ b/core/modules/migrate_drupal/tests/src/Kernel/d7/MigrateDrupal7AuditIdsTest.php
@@ -37,6 +37,7 @@ protected function setUp() {
     $this->installSchema('forum', ['forum_index']);
     $this->installSchema('node', ['node_access']);
     $this->installSchema('search', ['search_dataset']);
+    $this->installSchema('system', ['sequences']);
     $this->installSchema('tracker', ['tracker_node', 'tracker_user']);
 
     // Enable content moderation for nodes of type page.
diff --git a/core/modules/migrate_drupal/tests/src/Traits/CreateTestContentEntitiesTrait.php b/core/modules/migrate_drupal/tests/src/Traits/CreateTestContentEntitiesTrait.php
index 551e721..f30926c 100644
--- a/core/modules/migrate_drupal/tests/src/Traits/CreateTestContentEntitiesTrait.php
+++ b/core/modules/migrate_drupal/tests/src/Traits/CreateTestContentEntitiesTrait.php
@@ -2,16 +2,6 @@
 
 namespace Drupal\Tests\migrate_drupal\Traits;
 
-use Drupal\aggregator\Entity\Feed;
-use Drupal\aggregator\Entity\Item;
-use Drupal\block_content\Entity\BlockContent;
-use Drupal\comment\Entity\Comment;
-use Drupal\file\Entity\File;
-use Drupal\menu_link_content\Entity\MenuLinkContent;
-use Drupal\node\Entity\Node;
-use Drupal\taxonomy\Entity\Term;
-use Drupal\user\Entity\User;
-
 /**
  * Provides helper methods for creating test content.
  */
@@ -69,21 +59,21 @@ protected function createContent() {
         'url' => 'http://www.example.com',
       ]);
       $feed->save();
-    }
 
-    // Create an aggregator feed item.
-    if ($feed->id() && $entity_type_manager->hasDefinition('aggregator_item')) {
-      $item = $entity_type_manager->getStorage('aggregator_item')->create([
-        'title' => 'feed item',
-        'fid' => $feed->id(),
-        'link' => 'http://www.example.com',
-      ]);
-      $item->save();
+      // Create an aggregator feed item.
+      if ($feed->id() && $entity_type_manager->hasDefinition('aggregator_item')) {
+        $item = $entity_type_manager->getStorage('aggregator_item')->create([
+          'title' => 'feed item',
+          'fid' => $feed->id(),
+          'link' => 'http://www.example.com',
+        ]);
+        $item->save();
+      }
     }
 
     // Create a block content.
     if ($entity_type_manager->hasDefinition('block_content')) {
-      $block = $entity_type_manager->getStorage('aggregator_item')->create([
+      $block = $entity_type_manager->getStorage('block_content')->create([
         'info' => 'block',
         'type' => 'block',
       ]);
@@ -92,27 +82,27 @@ protected function createContent() {
 
     // Create a node.
     if ($entity_type_manager->hasDefinition('node')) {
-      $node = $entity_type_manager->getStorage('aggregator_item')->create([
+      $node = $entity_type_manager->getStorage('node')->create([
         'type' => 'page',
         'title' => 'page',
       ]);
       $node->save();
-    }
 
-    // Create a comment.
-    if ($entity_type_manager->hasDefinition('comment')) {
-      $comment = $entity_type_manager->getStorage('aggregator_item')->create([
-        'comment_type' => 'comment',
-        'field_name' => 'comment',
-        'entity_type' => 'node',
-        'entity_id' => $node->id(),
-      ]);
-      $comment->save();
+      // Create a comment.
+      if ($entity_type_manager->hasDefinition('comment')) {
+        $comment = $entity_type_manager->getStorage('comment')->create([
+          'comment_type' => 'comment',
+          'field_name' => 'comment',
+          'entity_type' => 'node',
+          'entity_id' => $node->id(),
+        ]);
+        $comment->save();
+      }
     }
 
     // Create a file.
     if ($entity_type_manager->hasDefinition('file')) {
-      $file = $entity_type_manager->getStorage('aggregator_item')->create([
+      $file = $entity_type_manager->getStorage('file')->create([
         'uri' => 'public://example.txt',
       ]);
       $file->save();
@@ -120,7 +110,7 @@ protected function createContent() {
 
     // Create a menu link.
     if ($entity_type_manager->hasDefinition('menu_link_content')) {
-      $menu_link = $entity_type_manager->getStorage('aggregator_item')->create([
+      $menu_link = $entity_type_manager->getStorage('menu_link_content')->create([
         'title' => 'menu link',
         'link' => ['uri' => 'http://www.example.com'],
         'menu_name' => 'tools',
@@ -130,7 +120,7 @@ protected function createContent() {
 
     // Create a taxonomy term.
     if ($entity_type_manager->hasDefinition('taxonomy_term')) {
-      $term = $entity_type_manager->getStorage('aggregator_item')->create([
+      $term = $entity_type_manager->getStorage('taxonomy_term')->create([
         'name' => 'term',
         'vid' => 'term',
       ]);
@@ -139,7 +129,7 @@ protected function createContent() {
 
     // Create a user.
     if ($entity_type_manager->hasDefinition('user')) {
-      $user = $entity_type_manager->getStorage('aggregator_item')->create([
+      $user = $entity_type_manager->getStorage('user')->create([
         'name' => 'user',
         'mail' => 'user@example.com',
       ]);
@@ -169,18 +159,19 @@ protected function createContentPostUpgrade() {
         'title' => 'Post upgrade page',
       ]);
       $node->save();
-    }
 
-    // Create a comment.
-    if ($entity_type_manager->hasDefinition('comment')) {
-      $comment = $entity_type_manager->getStorage('aggregator_item')->create([
-        'comment_type' => 'comment',
-        'field_name' => 'comment',
-        'entity_type' => 'node',
-        'entity_id' => $node->id(),
-      ]);
-      $comment->save();
+      // Create a comment.
+      if ($entity_type_manager->hasDefinition('comment')) {
+        $comment = $entity_type_manager->getStorage('aggregator_item')->create([
+          'comment_type' => 'comment',
+          'field_name' => 'comment',
+          'entity_type' => 'node',
+          'entity_id' => $node->id(),
+        ]);
+        $comment->save();
+      }
     }
+
     // Create a file.
     if ($entity_type_manager->hasDefinition('file')) {
       $file = $entity_type_manager->getStorage('file')->create([
diff --git a/core/modules/migrate_drupal_ui/tests/src/Functional/MigrateUpgradeExecuteTestBase.php b/core/modules/migrate_drupal_ui/tests/src/Functional/MigrateUpgradeExecuteTestBase.php
index 84f609f..a9d7de1 100644
--- a/core/modules/migrate_drupal_ui/tests/src/Functional/MigrateUpgradeExecuteTestBase.php
+++ b/core/modules/migrate_drupal_ui/tests/src/Functional/MigrateUpgradeExecuteTestBase.php
@@ -2,7 +2,6 @@
 
 namespace Drupal\Tests\migrate_drupal_ui\Functional;
 
-use Drupal\migrate\Plugin\MigrateIdMapInterface;
 use Drupal\migrate_drupal\MigrationConfigurationTrait;
 use Drupal\Tests\migrate_drupal\Traits\CreateTestContentEntitiesTrait;