docs: def WriteFileChunk(self, chunk):
      """Writes file chunk."""
      precondition.AssertType(chunk, bytes)
  
      if not self._stream:
        raise ArchiveAlreadyClosedError(
            "Attempting to write to a ZIP archive that was already closed.")
  
      self.cur_file_size += len(chunk)
      # TODO(user):pytype: crc32 is not visible outside of zipfile.
      # pytype: disable=module-attr
      self.cur_crc = zipfile.crc32(chunk, self.cur_crc) & 0xffffffff
      # pytype: enable=module-attr
  
      if self.cur_cmpr:
        chunk = self.cur_cmpr.compress(chunk)
        self.cur_compress_size += len(chunk)
  
      self._stream.write(chunk)
      return self._stream.GetValueAndReset()