diff --git a/core/modules/simpletest/src/TestBase.php b/core/modules/simpletest/src/TestBase.php
index 7b0a456..e862e62 100644
--- a/core/modules/simpletest/src/TestBase.php
+++ b/core/modules/simpletest/src/TestBase.php
@@ -237,7 +237,7 @@ protected function checkRequirements() {
    *
    * @see self::assert()
    */
-  protected function storeAssertion($assertion) {
+  protected function storeAssertion(array $assertion) {
     return self::getDatabaseConnection()
       ->insert('simpletest')
       ->fields($assertion)
@@ -331,7 +331,6 @@ public static function insertAssert($test_id, $test_class, $status, $message = '
       $status = $status ? 'pass' : 'fail';
     }
 
-    // We use t() here instead of $this->t(), since this method is static.
     $caller += array(
       'function' => 'Unknown',
       'line' => 0,
diff --git a/core/modules/simpletest/tests/src/Unit/TestBaseTest.php b/core/modules/simpletest/tests/src/Unit/TestBaseTest.php
index 992c3f2..f2ea830 100644
--- a/core/modules/simpletest/tests/src/Unit/TestBaseTest.php
+++ b/core/modules/simpletest/tests/src/Unit/TestBaseTest.php
@@ -86,8 +86,6 @@ public function testRandomString() {
    *
    * TestBase is abstract, so we have to mock it. We'll also
    * mock the storeAssertion() method so we don't need the database.
-   * And we'll also populate the stringTranslation property so that
-   * t() works.
    *
    * @return object
    *   Mock of Drupal\simpletest\TestBase.