code: def add_defined_filter(self, *value):
          
          filt = DefinedFilter(*value)
          self.update_filter(filt)
          return filt
docs: Add a DefinedFilter expression to the query. This filter will be
          considered true if the :class:`smc.monitoring.values.Value` instance
          has a value.
          
          .. seealso:: :class:`smc_monitoring.models.filters.DefinedFilter` for examples.
          
          :param Value value: single value for the filter. Value is of type
              :class:`smc_monitoring.models.values.Value`.
          :type: list(QueryFilter)
          :rtype: DefinedFilter