Future<Null> reverse({double from })

Starts running this animation in reverse (towards the beginning).

Returns a Future that completes when the animation is complete.

Source 

Future<Null> reverse({ double from }) {
  assert(() {
    if (duration == null) {
      throw new FlutterError(
        'AnimationController.reverse() called with no default Duration.\n'
        'The "duration" property should be set, either in the constructor or later, before '
        'calling the reverse() function.'
      );
    }
    return true;
  });
  _direction = _AnimationDirection.reverse;
  if (from != null)
    value = from;
  return animateTo(lowerBound);
}