@staticmethod
def p_if_data_xcp_optional(p):
    """if_data_xcp_optional : protocol_layer
                                | daq
                                | pag
                                | pgm
                                | segment
                                | daq_event
                                | xcp_on_can
                                | generic_parameter_list"""
    p[0] = p.slice[1].type, p[1]
