anchor.diff:  import 'animation.dart';
   import 'tween.dart';
   
  +// Examples can assume:
  +// AnimationController myAnimationController;
  +
   /// Enables creating an [Animation] whose value is defined by a sequence of
   /// [Tween]s.
   ///
  
positive.code: /// animation's duration. Each tween defines the animation's value during the
  /// interval indicated by its weight.
  ///
  /// For example, to define an animation that uses an easing curve to interpolate
  /// between 5.0 and 10.0 during the first 40% of the animation, remain at 10.0
  /// for the next 20%, and then return to 10.0 for the final 40%:
  ///
  /// ```dart
  /// final Animation<double> animation = TweenSequence(
  
negative.code: ///   ],
  /// ).animate(myAnimationController);
  /// ```
  /// {@end-tool}
  class TweenSequence<T> extends Animatable<T> {
    /// Construct a TweenSequence.
    ///
  