def on_cleanup_error(function, path, excinfo):
                click.secho("warning: failed to remove file or directory: {}\n"
                            "please delete it manually.".format(path),
                            fg="red")
def _option_suite(self, value):
        opt = Optional(value)
        self.assert_(isinstance(opt, Optional))
        self.assert_(isinstance(deoption(opt), type(value)))
        self.assertEqual(deoption(opt), value)