Index: wp-includes/class-wp-comment-query.php
===================================================================
--- wp-includes/class-wp-comment-query.php	(revision 41122)
+++ wp-includes/class-wp-comment-query.php	(working copy)
@@ -935,6 +935,8 @@
 	 * the descendant trees for all matched top-level comments.
 	 *
 	 * @since 4.4.0
+	 * 
+	 * @global wpdb $wpdb WordPress database abstraction object.
 	 *
 	 * @param array $comments Array of top-level comments whose descendants should be filled in.
 	 * @return array