Issue #21477: Idle htest: modify run; add more tests.
Patch by Saimadhav Heblikar. 2.7  backport of 90829, d7eea8f608c2.
diff --git a/Lib/idlelib/ClassBrowser.py b/Lib/idlelib/ClassBrowser.py
index c85340f..6183be9 100644
--- a/Lib/idlelib/ClassBrowser.py
+++ b/Lib/idlelib/ClassBrowser.py
@@ -13,7 +13,6 @@
 import os
 import sys
 import pyclbr
-import re
 
 from idlelib import PyShell
 from idlelib.WindowList import ListedToplevel
@@ -223,6 +222,7 @@
     name = os.path.splitext(file)[0]
     flist = PyShell.PyShellFileList(parent)
     ClassBrowser(flist, name, [dir], _htest=True)
+    parent.mainloop()
 
 if __name__ == "__main__":
     from idlelib.idle_test.htest import run