{
  "heartbeatFrequencyMS": 10000,
  "topology_description": {
    "type": "Unknown",
    "servers": [
      {
        "address": "a:27017",
        "type": "Unknown",
        "maxWireVersion": 6
      }
    ]
  },
  "read_preference": {
    "mode": "Nearest",
    "maxStalenessSeconds": 1
  },
  "suitable_servers": [],
  "in_latency_window": []
}