{
  "events": [
    {
      "type": "memberLeft",
      "source": {
        "groupId": "C1234567890",
        "type": "group"
      },
      "timestamp": 1553506027708,
      "mode": "active",
      "left": {
        "members": [
          {
            "userId": "U111111",
            "type": "user"
          }
        ]
      }
    }
  ],
  "destination": "Uab012345678901234567890123456789"
}