diff --git a/core/modules/comment/src/Tests/CommentFieldsTest.php b/core/modules/comment/src/Tests/CommentFieldsTest.php
index 144b900..b4de950 100644
--- a/core/modules/comment/src/Tests/CommentFieldsTest.php
+++ b/core/modules/comment/src/Tests/CommentFieldsTest.php
@@ -8,6 +8,7 @@
 namespace Drupal\comment\Tests;
 
 use Drupal\comment\Plugin\Field\FieldType\CommentItemInterface;
+use Drupal\Component\Utility\String;
 use Drupal\field\Entity\FieldStorageConfig;
 use Drupal\field\Entity\FieldConfig;
 
diff --git a/core/modules/content_translation/src/Tests/ContentTranslationUITest.php b/core/modules/content_translation/src/Tests/ContentTranslationUITest.php
index ef8160e..367840a 100644
--- a/core/modules/content_translation/src/Tests/ContentTranslationUITest.php
+++ b/core/modules/content_translation/src/Tests/ContentTranslationUITest.php
@@ -7,6 +7,7 @@
 
 namespace Drupal\content_translation\Tests;
 
+use Drupal\Component\Utility\String;
 use Drupal\Core\Entity\EntityInterface;
 use Drupal\Core\Entity\ContentEntityBase;
 use Drupal\Core\Language\Language;
diff --git a/core/modules/filter/src/Tests/FilterAPITest.php b/core/modules/filter/src/Tests/FilterAPITest.php
index 1c66b0c..be4a874 100644
--- a/core/modules/filter/src/Tests/FilterAPITest.php
+++ b/core/modules/filter/src/Tests/FilterAPITest.php
@@ -7,6 +7,7 @@
 
 namespace Drupal\filter\Tests;
 
+use Drupal\Component\Utility\String;
 use Drupal\Core\Session\AnonymousUserSession;
 use Drupal\Core\TypedData\OptionsProviderInterface;
 use Drupal\Core\TypedData\DataDefinition;
diff --git a/core/modules/forum/src/Tests/ForumBlockTest.php b/core/modules/forum/src/Tests/ForumBlockTest.php
index e28bafd..5badcbc 100644
--- a/core/modules/forum/src/Tests/ForumBlockTest.php
+++ b/core/modules/forum/src/Tests/ForumBlockTest.php
@@ -7,6 +7,7 @@
 
 namespace Drupal\forum\Tests;
 
+use Drupal\Component\Utility\String;
 use Drupal\simpletest\WebTestBase;
 use Drupal\Core\Datetime\DrupalDateTime;
 
diff --git a/core/modules/forum/src/Tests/ForumTest.php b/core/modules/forum/src/Tests/ForumTest.php
index de67f23..5ee40d8 100644
--- a/core/modules/forum/src/Tests/ForumTest.php
+++ b/core/modules/forum/src/Tests/ForumTest.php
@@ -7,6 +7,7 @@
 
 namespace Drupal\forum\Tests;
 
+use Drupal\Component\Utility\String;
 use Drupal\Core\Entity\EntityInterface;
 use Drupal\Core\Link;
 use Drupal\simpletest\WebTestBase;
diff --git a/core/modules/text/src/Tests/TextSummaryTest.php b/core/modules/text/src/Tests/TextSummaryTest.php
index f0925c5..2874f17 100644
--- a/core/modules/text/src/Tests/TextSummaryTest.php
+++ b/core/modules/text/src/Tests/TextSummaryTest.php
@@ -7,6 +7,7 @@
 
 namespace Drupal\text\Tests;
 
+use Drupal\Component\Utility\String;
 use Drupal\simpletest\DrupalUnitTestBase;
 
 /**