topology_description:
  type: Single
  servers:
  - &1
    address: a:27017
    avg_rtt_ms: 5
    type: Standalone
    tags:
      data_center: dc
operation: write
read_preference:
  mode: SecondaryPreferred
  tag_sets:
  - data_center: nyc
suitable_servers:
- *1
in_latency_window:
- *1