diff -u b/core/modules/node/tests/modules/node_access_test/node_access_test.module b/core/modules/node/tests/modules/node_access_test/node_access_test.module
--- b/core/modules/node/tests/modules/node_access_test/node_access_test.module
+++ b/core/modules/node/tests/modules/node_access_test/node_access_test.module
@@ -4,7 +4,7 @@
  * @file
  * Test module for testing the node access system.
  *
- * This module's functionality depends on two configuration variables:
+ * This module's functionality depends on the following state variables:
  * - node_access_test.no_access_uid: Used in NodeQueryAlterTest to enable the
  *   node_access_all grant realm.
  * - node_access_test.private: When TRUE, the module controls access for nodes
@@ -36,7 +36,7 @@
  *   the second group is added so that the interaction of multiple groups on
  *   a given grant realm can be tested in NodeAccessPagerTest.
  * - node_access_all: Provides grants for the user whose user ID matches the
- *   'node_access_test.no_access_uid' configuration variable. Access control on this
+ *   'node_access_test.no_access_uid' state variable. Access control on this
  *   realm is not provided in this module; instead,
  *   NodeQueryAlterTest::testNodeQueryAlterOverride() manually writes a node
  *   access record defining the access control for this realm.
@@ -48,7 +48,6 @@
  */
 function node_access_test_node_grants($account, $op) {
   $grants = array();
-  // First grant a grant to the author for own content.
   $grants['node_access_test_author'] = array($account->id());
   if ($op == 'view' && user_access('node test view', $account)) {
     $grants['node_access_test'] = array(8888, 8889);
@@ -65,7 +64,7 @@
  * Implements hook_node_access_records().
  *
  * By default, records are written for all nodes. When the
- * 'node_access_test.private' configuration variable is set to TRUE, records
+ * 'node_access_test.private' state variable is set to TRUE, records
  * are only written for nodes with a "private" property set, which causes the
  * Node module to write the default global view grant for nodes that are not
  * marked private.
@@ -116,7 +115,7 @@
  *
  * Provides a 'node test view' permission. By default, all content is
  * restricted, and users without this permission can only view content they
- * have authored. When the 'node_access_test.private' configuration variable is
+ * have authored. When the 'node_access_test.private' state variable is
  * TRUE, only 'private' nodes are restricted, and this permission grants access
  * to view private nodes.
  *
@@ -169,7 +168,6 @@
 /**
  * Implements hook_node_predelete().
  */
-
 function node_access_test_node_predelete(NodeInterface $node) {
   db_delete('node_access_test')->condition('nid', $node->id())->execute();
 }
@@ -190,6 +188,8 @@
 
 /**
  * Helper for node insert/update.
+ *
+ * Saves the private status of the node in the database.
  */
 function _node_access_test_node_write(NodeInterface $node) {
   db_merge('node_access_test')