def METHOD_NAME(conf, atom, test=False):
    try:
        is_present = __salt__["portage_config.is_present"](conf, atom)
    except Exception:  # pylint: disable=broad-except
        import traceback
        return {"result": False, "comment": traceback.format_exc()}
    if not is_present:
        if not test:
            __salt__["portage_config.append_to_package_conf"](conf, string=atom)
        return {"result": True}
    return {"result": None}