withPlainTime

pub fn withPlainTime(self: PlainDateTime, time: ?PlainTime) !PlainDateTime {
    const new_hour: u8 = if (time) |tt| tt.hour() else 0;
    const new_minute: u8 = if (time) |tt| tt.minute() else 0;
    const new_second: u8 = if (time) |tt| tt.second() else 0;
    const new_millisecond: u16 = if (time) |tt| tt.millisecond() else 0;
    const new_microsecond: u16 = if (time) |tt| tt.microsecond() else 0;
    const new_nanosecond: u16 = if (time) |tt| tt.nanosecond() else 0;

    const calendar_ptr = abi.c.temporal_rs_PlainDateTime_calendar(self._inner) orelse return error.TemporalError;
    const cal_id_view = abi.c.temporal_rs_Calendar_identifier(calendar_ptr);
    const cal_view = abi.c.DiplomatStringView{ .data = cal_id_view.data, .len = cal_id_view.len };
    const cal_result = abi.c.temporal_rs_AnyCalendarKind_parse_temporal_calendar_string(cal_view);
    const cal_kind = try abi.extractResult(cal_result);

    return wrapPlainDateTime(abi.c.temporal_rs_PlainDateTime_try_new(
        self.year(),
        self.month(),
        self.day(),
        new_hour,
        new_minute,
        new_second,
        new_millisecond,
        new_microsecond,
        new_nanosecond,
        cal_kind,
    ));
}