{
  "fictional": true,
  "post": "constructed-B",
  "clock": "UTC; two known observations of the same fictional post",
  "rows": [
    {
      "observedAt": "2026-10-31T09:00:00Z",
      "impressions": 300,
      "reactions": 12
    },
    {
      "observedAt": "2026-10-31T09:20:00Z",
      "impressions": 900,
      "reactions": 30
    }
  ],
  "expected": {
    "firstReactionEventRatio": 0.04,
    "laterReactionEventRatio": 0.03333333333333333,
    "invalidMixedTimeRatio": 0.1
  },
  "limitation": "Both counts are constructed and supplied. This cannot recover a missing historical measurement."
}