tor/data/flare.json",
          "transform": [
            {
              "type": "stratify",
              "key": "id",
              "parentKey": "parent"
            },
            {
              "type": "treemap",
              "field": "size",
              "sort": { "field": "value" },
              "round": true,
              "method": { "signal": "layout" },
              "ratio": { "signal": "aspectRatio" },
              "size": [{ "signal": "width" }, { "signal": "height" }]
            }
    