Returns the aggregated value for the metric

        :return: the value of the metric

def get_agg(self):
        """
        Returns the aggregated value for the metric

        :return: the value of the metric
        """
        """ Returns an aggregated value """
        query = self.get_query(False)
        res = self.get_metrics_data(query)
        # We need to extract the data from the JSON res
        # If we have agg data use it
        agg_id = str(ElasticQuery.AGGREGATION_ID)
        if 'aggregations' in res and 'values' in res['aggregations'][agg_id]:
            if self.AGG_TYPE == 'median':
                agg = res['aggregations'][agg_id]['values']["50.0"]
                if agg == 'NaN':
                    # ES returns NaN. Convert to None for matplotlib graph
                    agg = None
            else:
                raise RuntimeError("Multivalue aggregation result not supported")
        elif 'aggregations' in res and 'value' in res['aggregations'][agg_id]:
            agg = res['aggregations'][agg_id]['value']
        else:
            agg = res['hits']['total']

        return agg