@staticmethod
def p_if_data_module_optional(p):
    """if_data_module_optional : source
                                   | raster
                                   | event_group
                                   | seed_key
                                   | checksum
                                   | tp_blob tp_data
                                   | if_data_module_unsupported_element"""
    p[0] = p.slice[1].type, p[1]
