}
	// Read header
	if err := binary.Read(rs, binary.LittleEndian, &cdr.hdr); err != nil {
		return nil, err
	}
	if cdr.debug {
		fmt.Fprintf(os.Stderr, "=-= counter file header: %+v\n", cdr.hdr)
	}
	if !checkMagic(cdr.hdr.Magic) {
		return nil, fmt.Errorf("invalid magic string: not a counter data file")
	}
	if cdr.hdr.Version > coverage.CounterFileVersion {