updateRemainingDuration method
手动设置剩余时长
Implementation
void updateRemainingDuration(Duration duration) {
assert(duration.inMilliseconds >= 0, "剩余时长不能为负数");
// 确保设置的时长不为负
final validDuration =
duration.inMilliseconds < 0 ? Duration.zero : duration;
setRemainingDuration?.call(validDuration);
}