Update to Drupal 8.1.2. For more information, see https://www.drupal.org/project/drupal/releases/8.1.2

core/modules/simpletest/src/Tests/MissingDependentModuleUnitTest.php

@@ -0,0 +1,22 @@
+<?php
+
+namespace Drupal\simpletest\Tests;
+
+use Drupal\simpletest\KernelTestBase;
+
+/**
+ * This test should not load since it requires a module that is not found.
+ *
+ * @group simpletest
+ * @dependencies simpletest_missing_module
+ */
+class MissingDependentModuleUnitTest extends KernelTestBase {
+
+  /**
+   * Ensure that this test will not be loaded despite its dependency.
+   */
+  function testFail() {
+    $this->fail('Running test with missing required module.');
+  }
+
+}