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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 get_queryset(self, request):
 """ Annote the queryset with an 'is_active' property that's true iff that row is the most recently added row for that particular set of KEY_FIELDS values. Filter the queryset to show only is_active rows by default. """

        if request.GET.get(ShowHistoryFilter.parameter_name) == '1':
            queryset = self.model.objects.with_active_flag()
        else:
            # Show only the most recent row for each key.
            queryset = self.model.objects.current_set()
        ordering = self.get_ordering(request)
        if ordering:
            return queryset.order_by(*ordering)
        return queryset