method Temporal.PlainTime.prototype.roundround(roundTo: RoundTo< | "hour" | "minute" | "second" | "millisecond" | "microsecond" | "nanosecond">): Temporal.PlainTimeParametersroundTo: RoundTo< | "hour" | "minute" | "second" | "millisecond" | "microsecond" | "nanosecond">ReturnsTemporal.PlainTime