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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 wait_for_rsp(cls, timeout=None, callout=True):
 """IPMI Session Event loop iteration This watches for any activity on IPMI handles and handles registered by register_handle_callback. Callers are satisfied in the order that packets return from network, not in the order of calling. :param timeout: Maximum time to wait for data to come across. If unspecified, will autodetect based on earliest timeout """

        global iosockets
        # Assume:
        # Instance A sends request to packet B
        # Then Instance C sends request to BMC D
        # BMC D was faster, so data comes back before BMC B
        # Instance C gets to go ahead of Instance A, because
        # Instance C can get work done, but instance A cannot

        curtime = _monotonic_time()
        # There ar a number of parties that each has their own timeout
        # The caller can specify a deadline in timeout argument
        # each session with active outbound payload has callback to
        # handle retry/timout error
        # each session that is 'alive' wants to send a keepalive ever so often.
        # We want to make sure the most strict request is honored and block for
        # no more time than that, so that whatever part(ies) need to service in
        # a deadline, will be honored
        if timeout != 0:
            with util.protect(WAITING_SESSIONS):
                for session, parms in dictitems(cls.waiting_sessions):
                    if parms['timeout'] <= curtime:
                        timeout = 0  # exit after one guaranteed pass
                        break
                    if (timeout is not None and
                            timeout < parms['timeout'] - curtime):
                        continue  # timeout smaller than the current session
                        # needs
                    timeout = parms['timeout'] - curtime  # set new timeout
                    # value
            with util.protect(KEEPALIVE_SESSIONS):
                for session, parms in dictitems(cls.keepalive_sessions):
                    if parms['timeout'] <= curtime:
                        timeout = 0
                        break
                    if (timeout is not None and
                            timeout < parms['timeout'] - curtime):
                        continue
                    timeout = parms['timeout'] - curtime
        # If the loop above found no sessions wanting *and* the caller had no
        # timeout, exit function. In this case there is no way a session
        # could be waiting so we can always return 0
        while cls.iterwaiters:
            waiter = cls.iterwaiters.pop()
            waiter({'success': True})
            # cause a quick exit from the event loop iteration for calling code
            # to be able to reasonably set up for the next iteration before
            # a long select comes along
            if timeout is not None:
                timeout = 0
        if timeout is None:
            return 0
        if _poller(timeout=timeout):
            while sessionqueue:
                relsession = sessionqueue.popleft()
                relsession.process_pktqueue()
        sessionstodel = []
        sessionstokeepalive = []
        with util.protect(KEEPALIVE_SESSIONS):
            for session, parms in dictitems(cls.keepalive_sessions):
                # if the session is busy inside a command, defer invoking
                # keepalive until incommand is no longer the case
                if parms['timeout'] < curtime and not session._isincommand():
                    cls.keepalive_sessions[session]['timeout'] = \
                        _monotonic_time() + MAX_IDLE - (random.random() * 4.9)
                    sessionstokeepalive.append(session)
        for session in sessionstokeepalive:
            session._keepalive()
        with util.protect(WAITING_SESSIONS):
            for session, parms in dictitems(cls.waiting_sessions):
                if parms['timeout'] < curtime:  # timeout has expired, time to
                    # give up on it and trigger timeout
                    # response in the respective session
                    # defer deletion until after loop
                    sessionstodel.append(session)
                    # to avoid confusing the for loop
            for session in sessionstodel:
                cls.waiting_sessions.pop(session, None)
            # one loop iteration to make sure recursion doesn't induce
            # redundant timeouts
            for session in sessionstodel:
                session._timedout()
            return len(cls.waiting_sessions)