only in patch2:
unchanged:
--- a/core/tests/Drupal/Tests/Core/Config/StorageComparerTest.php
+++ b/core/tests/Drupal/Tests/Core/Config/StorageComparerTest.php
@@ -2,6 +2,7 @@
 
 namespace Drupal\Tests\Core\Config;
 
+use Drupal\Component\Serialization\PhpSerialize;
 use Drupal\Component\Uuid\Php;
 use Drupal\Core\Config\StorageComparer;
 use Drupal\Tests\UnitTestCase;
@@ -45,6 +46,12 @@ protected function setUp() {
     $this->sourceStorage = $this->getMock('Drupal\Core\Config\StorageInterface');
     $this->targetStorage = $this->getMock('Drupal\Core\Config\StorageInterface');
     $this->configManager = $this->getMock('Drupal\Core\Config\ConfigManagerInterface');
+    $container = $this->getMock('Symfony\Component\DependencyInjection\ContainerInterface');
+    $container->expects($this->any())
+      ->method('get')
+      ->with('serialization.phpserialize')
+      ->willReturn(new PhpSerialize());
+    \Drupal::setContainer($container);
     $this->storageComparer = new StorageComparer($this->sourceStorage, $this->targetStorage, $this->configManager);
   }