def METHOD_NAME(arg: str) -> CheckerConfig:
    """
    This function can be used at "type" argument of argparse.add_argument().
    It checks the format of --checker-config flag:
    <analyzer>:<checker>:<option>=<value>
    These four things return as a tuple.
    """
    m = re.match(
        r"(?P<analyzer>.+):(?P<checker>.+):(?P<option>.+)=(?P<value>.+)", arg)
    if not m:
        raise argparse.ArgumentTypeError(
            f"Checker option in wrong format: {arg}, should be "
            "<analyzer>:<checker>:<option>=<value>")
    return CheckerConfig(
        m.group("analyzer"), m.group("checker"),
        m.group("option"), m.group("value"))