def seek(self, offset, whence=os.SEEK_SET):
    if not self._is_open:
      raise IOError(u'Not opened.')

    if whence == os.SEEK_CUR:
      offset += self._current_offset
    elif whence == os.SEEK_END:
      offset += self._uncompressed_stream_size
    elif whence != os.SEEK_SET:
      raise IOError(u'Unsupported whence.')

    if offset < 0:
      raise IOError(u'Invalid offset value less than zero.')

    if offset != self._current_offset:
      self._current_offset = offset
      self._realign_offset = True
remove a recurrence instance from a VEVENT's RRDATE list
dataset/ETHPy150Open log2timeline/dfvfs/dfvfs/file_io/zip_file_io.py/ZipFile.seek--crossover with--dataset/ETHPy150Open pimutils/khal/khal/khalendar/aux.py/_add_exdate