code: def get_size(self):
      
      if not self._is_open:
        raise IOError('Not opened.')
  
      if self._uncompressed_stream_size is None:
        self._uncompressed_stream_size = self._GetUncompressedStreamSize()
  
      return self._uncompressed_stream_size
docs: Retrieves the size of the file-like object.
  
      Returns:
        int: size of the uncompressed stream.
  
      Raises:
        IOError: if the file-like object has not been opened.
        OSError: if the file-like object has not been opened.