Fraction (0-1) of the requested prepare window that actually holds data,
reported by the backend once preparation completes. Present only on the
final preparing event.
Optionalpercent
percent?:number
0-100 when size is known. Undefined during stage start.
Fraction (0-1) of the requested prepare window that actually holds data, reported by the backend once preparation completes. Present only on the final
preparingevent.