{
  "kind": "recv",
  "partner": "B",
  "branches": [
    {
      "label": {
        "name": "m2",
        "sort": "unit"
      },
      "continuation": {
        "kind": "send",
        "partner": "D",
        "branches": [
          {
            "label": {
              "name": "m3",
              "sort": "unit"
            },
            "continuation": {
              "kind": "end"
            }
          }
        ]
      }
    }
  ]
}
