diff --git a/core/modules/simpletest/src/TestBase.php b/core/modules/simpletest/src/TestBase.php
index b4901af..b59b9f3 100644
--- a/core/modules/simpletest/src/TestBase.php
+++ b/core/modules/simpletest/src/TestBase.php
@@ -400,15 +400,8 @@ protected function assert($status, $message = '', $group = 'Other', array $calle
 
     // We do not use a ternary operator here to allow a breakpoint on
     // test failure.
-    if ($status == 'pass') {
-      return TRUE;
-    }
-    else {
-      if ($this->dieOnFail && ($status == 'fail' || $status == 'exception')) {
-        exit(1);
-      }
       return FALSE;
-    }
+
   }
 
   /**
diff --git a/core/tests/Drupal/Tests/UnitTestCase.php b/core/tests/Drupal/Tests/UnitTestCase.php
index d6deb9e..9548ed2 100644
--- a/core/tests/Drupal/Tests/UnitTestCase.php
+++ b/core/tests/Drupal/Tests/UnitTestCase.php
@@ -36,7 +36,6 @@
    * {@inheritdoc}
    */
   protected function setUp() {
-    parent::setUp();
     // Ensure that an instantiated container in the global state of \Drupal from
     // a previous test does not leak into this test.
     \Drupal::setContainer(NULL);