self.assertEqual('/usr/bin/hello editors/emacs,python/hello,utils/sl\n', \
cw.formatline('/usr/bin/hello', ['editors/emacs', 'python/hello', 'utils/sl']))
# test output_filename
self.assertEqual('/usr/bin/hello editors/emacs,python/hello,utils/sl\n', \
cw.formatline('/usr/bin/hello', ['editors/emacs', 'python/hello', 'utils/sl']))
# test output_filename