def parse_response_adu(resp_adu, req_adu=None):
resp_pdu = resp_adu[<NUM_LIT:7>:]<EOL>function = create_function_from_response_pdu(resp_pdu, req_adu)<EOL>return function.data<EOL>
Parse response ADU and return response data. Some functions require
    request ADU to fully understand request ADU.

    :param resp_adu: Resonse ADU.
    :param req_adu: Request ADU, default None.
    :return: Response data.