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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 dispatch(self,request,*args,**kwargs):
        '''
        Handle the session data passed by the prior view.
        '''

        lessonSession = request.session.get(PRIVATELESSON_VALIDATION_STR,{})

        try:
            self.lesson = PrivateLessonEvent.objects.get(id=lessonSession.get('lesson'))
        except (ValueError, ObjectDoesNotExist):
            messages.error(request,_('Invalid lesson identifier passed to sign-up form.'))
            return HttpResponseRedirect(reverse('bookPrivateLesson'))

        expiry = parse_datetime(lessonSession.get('expiry',''),)
        if not expiry or expiry < timezone.now():
            messages.info(request,_('Your registration session has expired. Please try again.'))
            return HttpResponseRedirect(reverse('bookPrivateLesson'))

        self.payAtDoor = lessonSession.get('payAtDoor',False)
        return super(PrivateLessonStudentInfoView,self).dispatch(request,*args,**kwargs)