{
  "topology_description": {
    "type": "ReplicaSetWithPrimary",
    "servers": [
      {
        "address": "b:27017",
        "avg_rtt_ms": 5,
        "type": "RSSecondary",
        "tags": {
          "data_center": "nyc"
        }
      },
      {
        "address": "c:27017",
        "avg_rtt_ms": 100,
        "type": "RSSecondary",
        "tags": {
          "data_center": "nyc"
        }
      },
      {
        "address": "a:27017",
        "avg_rtt_ms": 26,
        "type": "RSPrimary",
        "tags": {
          "data_center": "nyc"
        }
      }
    ]
  },
  "operation": "read",
  "read_preference": {
    "mode": "Secondary",
    "tag_sets": [
      {
        "data_center": "sf"
      }
    ]
  },
  "suitable_servers": [],
  "in_latency_window": []
}