fw = &fileWriter{
			zipw:      w.cw,
			compCount: &countWriter{w: w.cw},
			crc32:     crc32.NewIEEE(),
		}
		comp := w.compressor(fh.Method)
		if comp == nil {
			return nil, ErrAlgorithm
		}
		var err error
		fw.comp, err = comp(fw.compCount)
		if err != nil {
			return nil, err
		}
		fw.rawCount = &countWriter{w: fw.comp}
		fw.header = h
		ow = fw
	}