def getIdHexChars(id):
    """ get the hex chars of the given id """
    if id[0] == 'c':
        # don't include chunk index
        index = id.index('_')
        parts = id[0:index].split('-')
    else:
        parts = id.split('-')
    if len(parts) != 6:
        raise ValueError(f"Unexpected id format for uuid: {id}")
    return "".join(parts[1:])