{
  "scope": "Synthetic exact-rational arithmetic only; no browser, CDP, renderer, model, or performance test.",
  "fps": "60",
  "duration_seconds": "2",
  "frame_count": 120,
  "first_frame_seconds": "0",
  "last_frame_seconds": "119/60",
  "endpoint_convention": "120 frames on [0, 2); the last sample is 119/60 seconds, not 2 seconds.",
  "velocity_units_per_second": "120",
  "naive_increment_per_update": "2",
  "ideal_last_capture_position": "238",
  "callbacks": {
    "regular_30": {
      "update_count_through_2_seconds": 60,
      "last_callback_seconds": "2",
      "elapsed_position_at_2_seconds": "240",
      "naive_position_at_2_seconds": "120",
      "elapsed_held_at_last_capture": "236",
      "max_capture_hold_lag_units": "2"
    },
    "regular_60": {
      "update_count_through_2_seconds": 120,
      "last_callback_seconds": "2",
      "elapsed_position_at_2_seconds": "240",
      "naive_position_at_2_seconds": "240",
      "elapsed_held_at_last_capture": "238",
      "max_capture_hold_lag_units": "0"
    },
    "irregular": {
      "update_count_through_2_seconds": 120,
      "last_callback_seconds": "2",
      "elapsed_position_at_2_seconds": "240",
      "naive_position_at_2_seconds": "240",
      "elapsed_held_at_last_capture": "237",
      "max_capture_hold_lag_units": "1"
    }
  }
}