How to use the chaostoolkit.check.check_newer_version function in chaostoolkit

def test_version_is_newer(requests):
    version = __version__.replace("rc", "-rc")
    newer_version = semver.bump_minor(version)
    requests.get.return_value = FakeResponse(
        200,
        "http://someplace//usage/latest/",
        {"version": __version__, "up_to_date": False}
    )

    latest_version = check_newer_version(command="init")
    assert latest_version == __version__

def test_version_is_not_newer(requests):
    requests.get.return_value = FakeResponse(
        200,
        "https://releases.chaostoolkit.org/latest",
        {"version": __version__, "up_to_date": True}
    )

    latest_version = check_newer_version(command="init")
    assert latest_version is None

configure_logger(
            verbose=verbose, log_file=log_file, log_format=log_format,
            context_id=str(uuid.uuid4()))

    subcommand = ctx.invoked_subcommand

    # make it nicer for going through the log file
    logger.debug("#" * 79)
    logger.debug("Running command '{}'".format(subcommand))

    ctx.obj = {}
    ctx.obj["settings_path"] = click.format_filename(settings)
    logger.debug("Using settings file '{}'".format(ctx.obj["settings_path"]))

    if not no_version_check:
        check_newer_version(command=subcommand)

    if change_dir:
        logger.warning("Moving to {d}".format(d=change_dir))
        os.chdir(change_dir)