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 flush(self):
        if self._bufferedCommands is None:
            return
        self._connection.sendline(str(self._bufferedCommands))
        self._bufferedCommands = None