CogmapStaleness

Map-level staleness readout (cogmap_staleness): when the shape was last materialized, the latest
touch to the map's regions/edges, and whether the read is stale. Staleness is LEGIBLE — reported,
never blocking. materialized_at is None when the map has never been materialized.

{
    "is_stale": true,
    "latest_touch": "2019-08-24T14:15:22.123Z",
    "materialized_at": "2019-08-24T14:15:22.123Z"
}