Issue #22629: Revise idle_test.htest, mostly docstring.  Start revision of
htests to add # htest # marker for coveragepy and stop tcl errors.
diff --git a/Lib/idlelib/GrepDialog.py b/Lib/idlelib/GrepDialog.py
index 77195b9..afb9a21 100644
--- a/Lib/idlelib/GrepDialog.py
+++ b/Lib/idlelib/GrepDialog.py
@@ -131,7 +131,7 @@
             self.top.withdraw()
 
 
-def _grep_dialog(parent):  # for htest
+def _grep_dialog(parent):  # htest #
     from idlelib.PyShell import PyShellFileList
     root = Tk()
     root.title("Test GrepDialog")