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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def search_service_code(self, service_index):
 """Search for a service code that corresponds to an index. The Search Service Code command provides access to the iterable list of services and areas within the activated system. The *service_index* argument may be any value from 0 to 0xffff. As long as there is a service or area found for a given *service_index*, the information returned is a tuple with either one or two 16-bit integer elements. Two integers are returned for an area definition, the first is the area code and the second is the largest possible service index for the area. One integer, the service code, is returned for a service definition. The return value is :const:`None` if the *service_index* was not found. For example, to print all services and areas of the active system: :: for i in xrange(0x10000):
 area_or_service = tag.search_service_code(i) if area_or_service is None: break elif len(area_or_service) == 1: sc = area_or_service[0] print(nfc.tag.tt3.ServiceCode(sc >> 6, sc & 0x3f)) elif len(area_or_service) == 2: area_code, area_last = area_or_service print("Area {0:04x}--{0:04x}".format(area_code, area_last)) Command execution errors raise :exc:`~nfc.tag.TagCommandError`. """

        log.debug("search service code index {0}".format(service_index))
        # The maximum response time is given by the value of PMM[3].
        # Some cards (like RC-S860 with IC RC-S915) encode a value
        # that is too short, thus we use at lest 2 ms.
        a, e = self.pmm[3] & 7, self.pmm[3] >> 6
        timeout = max(302E-6 * (a + 1) * 4**e, 0.002)
        data = pack("<H", service_index)
        data = self.send_cmd_recv_rsp(0x0A, data, timeout, check_status=False)
        if data != "\xFF\xFF":
            unpack_format = "<H" if len(data) == 2 else "<HH"
            return unpack(unpack_format, data)