{
  "topology_description": {
    "type": "ReplicaSetWithPrimary",
    "servers": [
      {
        "address": "a:27017",
        "type": "RSPrimary",
        "avg_rtt_ms": 5,
        "lastUpdateTime": 0,
        "maxWireVersion": 6,
        "lastWrite": {
          "lastWriteDate": {
            "$numberLong": "2"
          }
        }
      },
      {
        "address": "b:27017",
        "type": "RSSecondary",
        "avg_rtt_ms": 5,
        "lastUpdateTime": 0,
        "maxWireVersion": 6,
        "lastWrite": {
          "lastWriteDate": {
            "$numberLong": "1"
          }
        }
      }
    ]
  },
  "read_preference": {
    "mode": "Nearest",
    "maxStalenessSeconds": 0
  },
  "error": true
}