{
  "trace": "pre_Exp4.trace",
  "features": [
    {
      "feature": "AP4",
      "extracts": [
        {
          "src": {
            "class": "E",
            "id": null
          }, 
          "dst": {
            "class": "C",
            "id": null
          }, 
          "type": "Container-Component",
          "order": "0"
        }
      ]
    }
  ]
}