Create history_filename with INITHISTORY if it doesn't exist.

def create_history_filename(self):
        """Create history_filename with INITHISTORY if it doesn't exist."""
        if self.history_filename and not osp.isfile(self.history_filename):
            try:
                encoding.writelines(self.INITHISTORY, self.history_filename)
            except EnvironmentError:
                pass