Optional ReadonlybuildObserved queue kind; absent when its native reference/category is unavailable.
ReadonlypositionSnapshot position, not a persistent job identity.
ReadonlyprogressCompleted fraction, from 0 to 1; null when unreadable.
ReadonlyremainingRemaining game seconds, or null when unavailable.
ReadonlytotalPositive total game seconds, or null when unavailable.
Readonlytype
A game-time snapshot. Null means unobserved/uninitialized; never advance on a wall clock.