{
  "description":"switch the buzzer",
  "spec": {
    "id": "__HOPE__/demo/tank/buzzer/buzz",
    "in": {
      "ports": [{
        "name": "on",
        "type": "boolean"
        }]
    },
    "out": {
      "ports": [{
        "name": "status",
        "type": "boolean"
      }]
    }
  }
}