code: def invertedFrameRange(self, zfill=0):
          
          result = []
          frames = sorted(self.items)
          for idx, frame in enumerate(frames[:-1]):
              next_frame = frames[idx + 1]
              if next_frame - frame != 1:
                  r = xrange(frame + 1, next_frame)
                  # Check if the next update to the result set
                  # will exceed out max frame size.
                  # Prevent memory overflows.
                  self._maxSizeCheck(len(r) + len(result))
                  result += r
  
          if not result:
              return ''
  
          return FrameSet.framesToFrameRange(
              result, zfill=zfill, sort=False, compress=False)
docs: Return the inverse of the :class:`FrameSet` 's frame range, padded if
          desired.
          The inverse is every frame within the full extent of the range.
  
          Examples:
              >>> FrameSet('1-100x2').invertedFrameRange()
              '2-98x2'
              >>> FrameSet('1-100x2').invertedFrameRange(5)
              '00002-00098x2'
  
          If the inverted frame size exceeds `fileseq.constants.MAX_FRAME_SIZE`,
          a ``MaxSizeException`` will be raised.
  
          Args:
              zfill (int): the width to use to zero-pad the frame range string
  
          Returns:
              str:
  
          Raises:
              :class:`fileseq.exceptions.MaxSizeException`: