code: def queryset(self, request, queryset):
          
  
          value = self.value()
          try:
              if not value:
                  return queryset
              prefix, period = value.split(':')
              if prefix == 'create':
                  return queryset.created_on(period)
              elif prefix == 'update':
                  return queryset.updated_on(period)
              elif prefix == 'both':
                  return queryset.created_or_updated_on(period)
              else:
                  return queryset
          except ValueError:
              return queryset
docs: Will invoke .created_on(period) or .updated_on(period) depending on how it is specified in
            each subclass (A queryset obtained from the Tracked* models will have a created_on and
            updated_on models as shortcuts).
          :param request:
          :param queryset:
          :return: filtered queryset.