func (r *metacacheReader) peek() (metaCacheEntry, error) {
	r.checkInit()
	if r.err != nil {
		return metaCacheEntry{}, r.err
	}
	if r.current.name != "" {
		return r.current, nil
	}
	if more, err := r.mr.ReadBool(); !more {
		switch err {
		case nil:
			r.err = io.EOF
			return metaCacheEntry{}, io.EOF
		case io.EOF:
			r.err = io.ErrUnexpectedEOF
			return metaCacheEntry{}, io.ErrUnexpectedEOF
		}