code: def show_event_view(request):
      
      if request.method == "POST":
          event_id = request.POST.get("event_id")
          if event_id:
              event = Event.objects.get(id=event_id)
              event.user_map.users_hidden.remove(request.user)
              event.user_map.save()
              return http.HttpResponse("Unhidden")
          raise http.Http404
      else:
          return http.HttpResponseNotAllowed(["POST"], "HTTP 405: METHOD NOT ALLOWED")
docs: Unhide an event that was hidden by the logged-in user.
  
          events_hidden in the user model is the related_name for
          "users_hidden" in the EventUserMap model.