def METHOD_NAME(
    self, nested_severity_ruleset
):
    for expressions, modifier in SeverityRules._parse_raw_severity_rules(
        nested_severity_ruleset
    ):
        assert callable(
            modifier
        ), f"modifier isn't callable for rule {expressions!r}"
        assert isinstance(
            modifier(Severity(3)), int
        ), f"modifier does not follow protocol for rule {expressions!r}"