Timer constructor Null safety

Timer(
  1. Duration duration,
  2. void callback(
      )
    )

    Creates a new timer.

    The callback function is invoked after the given duration.

    Implementation

    factory Timer(Duration duration, void Function() callback) {
  if (Zone.current == Zone.root) {
    // No need to bind the callback. We know that the root's timer will
    // be invoked in the root zone.
    return Zone.current.createTimer(duration, callback);
  }
  return Zone.current
      .createTimer(duration, Zone.current.bindCallbackGuarded(callback));
}