def METHOD_NAME(payload: WildValue) -> str:
    type = payload["source"]["_meta"]["type"].tame(check_string)
    if type == "teammate":
        first_name = payload["source"]["data"]["first_name"].tame(check_string)
        last_name = payload["source"]["data"]["last_name"].tame(check_string)
        return f"{first_name} {last_name}"
    elif type == "rule":
        name = payload["source"]["data"]["name"].tame(check_string)
        return f"'{name}' rule"
    return f"({type})"