1 files changed, 8 insertions, 0 deletions
diff --git a/modules/simpletest/drupal_web_test_case.php b/modules/simpletest/drupal_web_test_case.php
index 945cbe9d0..323825ac2 100644
--- a/modules/simpletest/drupal_web_test_case.php
+++ b/modules/simpletest/drupal_web_test_case.php
@@ -582,6 +582,14 @@ class DrupalUnitTestCase extends DrupalTestCase {
     $this->skipClasses[__CLASS__] = TRUE;
   }
 
+  /**
+   * Sets up unit test environment.
+   *
+   * Unlike DrupalWebTestCase::setUp(), DrupalUnitTestCase::setUp() does not
+   * install modules because tests are performed without accessing the database.
+   * Any required files must be explicitly included by the child class setUp()
+   * method.
+   */
   protected function setUp() {
     global $conf;