only in patch2:
unchanged:
--- /dev/null
+++ b/core/modules/ckeditor/tests/src/Plugin/CKEditorPlugin/LanguageTest.php
@@ -0,0 +1,42 @@
+<?php
+
+namespace Drupal\Tests\ckeditor\Unit\Plugin\CKEditorPlugin;
+
+use Drupal\ckeditor\Plugin\CKEditorPlugin\Language;
+use Drupal\Tests\UnitTestCase;
+
+/**
+ * @coversDefaultClass \Drupal\ckeditor\Plugin\CKEditorPlugin\Language
+ */
+class LanguageTest extends UnitTestCase {
+
+  /**
+   * The plugin under test.
+   *
+   * @var \Drupal\ckeditor\Plugin\CKEditorPlugin\Language
+   */
+  protected $plugin;
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setUp() {
+    $this->plugin = new Language(array(), $this->randomMachineName(), array());
+  }
+
+  /**
+   * @covers ::getConfig
+   */
+  public function testGetConfig() {
+    $editor = $this->getMockBuilder('Drupal\editor\Entity\Editor')
+      ->disableOriginalConstructor()
+      ->getMock();
+
+    $config = $this->plugin->getConfig($editor);
+
+    $this->assertInternalType('array', $config);
+    $this->assertTrue(in_array('nl:Dutch', $config['language_list']));
+    $this->assertTrue(in_array('ar:Arabic:rtl', $config['language_list']));
+  }
+
+}