code: def padFrameRange(frange, zfill):
          
          def _do_pad(match):
              """
              Substitutes padded for unpadded frames.
              """
              result = list(match.groups())
              result[1] = pad(result[1], zfill)
              if result[4]:
                  result[4] = pad(result[4], zfill)
              return ''.join((i for i in result if i))
          return PAD_RE.sub(_do_pad, frange)
docs: Return the zero-padded version of the frame range string.
  
          Args:
              frange (str): a frame range to test
              zfill (int):
  
          Returns:
              str: