maybeTimeout method
Implementation
Future<T> maybeTimeout(Duration? duration, FutureOr<T> onTimeout()) {
  if (duration == null) return this;
  if (duration.inMicroseconds <= 0) return this;
  return this.timeout(duration, onTimeout: onTimeout);
}Future<T> maybeTimeout(Duration? duration, FutureOr<T> onTimeout()) {
  if (duration == null) return this;
  if (duration.inMicroseconds <= 0) return this;
  return this.timeout(duration, onTimeout: onTimeout);
}