"refId": "A",
          "datasource": {
            "uid": "${datasource}",
            "type": "prometheus"
          }
        },
        {
          "expr": "label_join(sum(rate(istio_tcp_sent_bytes_total{reporter=\"source\"}[1m])) by (destination_workload, destination_workload_namespace, destination_service), \"destination_workload_var\", \".\", \"destination_workload\", \"destination_workload_namespace\")",