cr := newReader(bytes.NewBuffer(in.input))
				all := dst[:0]
				err := func() error {
					// Read all records until EOF or another error.
					for {
						record, err := cr.Read()
						if err == io.EOF {
							return nil
						}
						if err != nil {
							return errCSVParsingError(err)
						}
						var recDst []string
						if len(dst) > len(all) {
							recDst = dst[len(all)]
						}

		if etag := r.ETag(); !Equal(etag, r.checksum) {
			return n, VerifyError{
				Expected: r.checksum,
				Computed: etag,
			}
		}
	}
	return n, err
}

// ETag returns the ETag of all the content read
// so far. Reading more content changes the MD5
// checksum. Therefore, calling ETag multiple
// times may return different results.
func (r *Reader) ETag() ETag {
	sum := r.md5.Sum(nil)