code: def _pad_block(self):
      
      pad_length = _BLOCK_SIZE - self.__position % _BLOCK_SIZE
      if pad_length and pad_length != _BLOCK_SIZE:
        self.__writer.write('\x00' * pad_length)
        self.__position += pad_length
docs: Pad block with 0.
  
      Pad current block with 0. Reader will simply treat these as corrupted
      record and skip the block.
  
      This method is idempotent.