<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def frame_info(self):
 """Return a string identifying the current frame."""

        if not self._logger.isEnabledFor(logging.DEBUG):
            return ''
        f = sys._getframe(3)
        fname = os.path.split(f.f_code.co_filename)[1]
        return '{}:{}'.format(fname, f.f_lineno)