diff --git a/core/modules/views/lib/Drupal/views/Tests/BasicTest.php b/core/modules/views/lib/Drupal/views/Tests/BasicTest.php
index d66d304..a4511f3 100644
--- a/core/modules/views/lib/Drupal/views/Tests/BasicTest.php
+++ b/core/modules/views/lib/Drupal/views/Tests/BasicTest.php
@@ -9,6 +9,17 @@
 
 /**
  * Basic test class for Views query builder tests.
+ *
+ * To make a Views unit test outside the Views module:
+ * - Use the namespace \Drupal\<module_name>\Tests\Views.
+ * - Define the test module default view at
+ *   tests/modules/<module_name>/test_views/views.view.<machine_name>.yml.
+ * - Implement setUp() and call ViewTestData::importTestViews() passing the
+ *   module containing the default test view.
+ * - Probably modify viewsData() and dataSet() to change basic information
+ *   provided by ViewUnitTestBase.
+ *
+ * @see \Drupal\file\Tests\Views\ExtensionViewsFieldTest
  */
 class BasicTest extends ViewUnitTestBase {
 
diff --git a/core/modules/views/lib/Drupal/views/Tests/ViewUnitTestBase.php b/core/modules/views/lib/Drupal/views/Tests/ViewUnitTestBase.php
index 134b97a..2aa6e45 100644
--- a/core/modules/views/lib/Drupal/views/Tests/ViewUnitTestBase.php
+++ b/core/modules/views/lib/Drupal/views/Tests/ViewUnitTestBase.php
@@ -21,6 +21,7 @@
  *
  * @see \Drupal\views\Tests\ViewTestBase
  * @see \Drupal\simpletest\DrupalUnitTestBase
+ * @see \Drupal\views\Tests\BasicTest
  */
 abstract class ViewUnitTestBase extends DrupalUnitTestBase {