diff -u b/core/modules/views/tests/src/Unit/Plugin/HandlerBaseTest.php b/core/modules/views/tests/src/Unit/Plugin/HandlerBaseTest.php
--- b/core/modules/views/tests/src/Unit/Plugin/HandlerBaseTest.php
+++ b/core/modules/views/tests/src/Unit/Plugin/HandlerBaseTest.php
@@ -106,13 +106,13 @@
    * @return bool
    *   TRUE if the assertion succeeded, FALSE otherwise.
    */
-function t($string, array $args = array(), array $options = array()) {
-  return \Drupal::translation()->translate($string, $args, $options);
-}
+  protected function t($string, array $args = array(), array $options = array()) {
+    return \Drupal::translation()->translate($string, $args, $options);
+  }
 
   protected function assertEqualValue($expected, $handler, $message = '', $group = 'Other') {
     if (empty($message)) {
-      $message = t('Comparing @first and @second', array('@first' => implode(',', $expected), '@second' => implode(',', $handler->value)));
+      $message = $this->t('Comparing @first and @second', array('@first' => implode(',', $expected), '@second' => implode(',', $handler->value)));
     }
 
     return $this->assert($expected == $handler->value, $message, $group);