anchor.diff:  
   /// A collection of common animation curves.
   ///
  -/// ![](https://flutter.github.io/assets-for-api-docs/assets/animation/curve_bounce_in.png)
  -/// ![](https://flutter.github.io/assets-for-api-docs/assets/animation/curve_bounce_in_out.png)
  -/// ![](https://flutter.github.io/assets-for-api-docs/assets/animation/curve_bounce_out.png)
  -/// ![](https://flutter.github.io/assets-for-api-docs/assets/animation/curve_decelerate.png)
  -/// ![](https://flutter.github.io/assets-for-api-docs/assets/animation/curve_ease.png)
  -/// ![](https://flutter.github.io/assets-for-api-docs/assets/animation/curve_ease_in.png)
  -/// ![](https://flutter.github.io/assets-for-api-docs/assets/animation/curve_ease_in_out.png)
  -/// ![](https://flutter.github.io/assets-for-api-docs/assets/animation/curve_ease_out.png)
  -/// ![](https://flutter.github.io/assets-for-api-docs/assets/animation/curve_elastic_in.png)
  -/// ![](https://flutter.github.io/assets-for-api-docs/assets/animation/curve_elastic_in_out.png)
  -/// ![](https://flutter.github.io/assets-for-api-docs/assets/animation/curve_elastic_out.png)
  -/// ![](https://flutter.github.io/assets-for-api-docs/assets/animation/curve_fast_out_slow_in.png)
  -/// ![](https://flutter.github.io/assets-for-api-docs/assets/animation/curve_linear.png)
  +/// {@animation 464 192 https://flutter.github.io/assets-for-api-docs/assets/animation/curve_bounce_in.mp4}
  +/// {@animation 464 192 https://flutter.github.io/assets-for-api-docs/assets/animation/curve_bounce_in_out.mp4}
  +/// {@animation 464 192 https://flutter.github.io/assets-for-api-docs/assets/animation/curve_bounce_out.mp4}
  +/// {@animation 464 192 https://flutter.github.io/assets-for-api-docs/assets/animation/curve_decelerate.mp4}
  +/// {@animation 464 192 https://flutter.github.io/assets-for-api-docs/assets/animation/curve_ease.mp4}
  +/// {@animation 464 192 https://flutter.github.io/assets-for-api-docs/assets/animation/curve_ease_in.mp4}
  +/// {@animation 464 192 https://flutter.github.io/assets-for-api-docs/assets/animation/curve_ease_in_out.mp4}
  +/// {@animation 464 192 https://flutter.github.io/assets-for-api-docs/assets/animation/curve_ease_out.mp4}
  +/// {@animation 464 192 https://flutter.github.io/assets-for-api-docs/assets/animation/curve_elastic_in.mp4}
  +/// {@animation 464 192 https://flutter.github.io/assets-for-api-docs/assets/animation/curve_elastic_in_out.mp4}
  +/// {@animation 464 192 https://flutter.github.io/assets-for-api-docs/assets/animation/curve_elastic_out.mp4}
  +/// {@animation 464 192 https://flutter.github.io/assets-for-api-docs/assets/animation/curve_fast_out_slow_in.mp4}
  +/// {@animation 464 192 https://flutter.github.io/assets-for-api-docs/assets/animation/curve_linear.mp4}
   ///
   /// See also:
   ///
  
positive.code: /// set to 1.0 will essentially become a three-second animation that starts
  /// three seconds later.
  ///
  /// ![](https://flutter.github.io/assets-for-api-docs/assets/animation/curve_interval.png)
  class Interval extends Curve {
    /// Creates an interval curve.
    ///
  
negative.code: /// An instance of this class using the default period of 0.4 is available as
  /// [Curves.elasticIn].
  ///
  /// {@animation 464 192 https://flutter.github.io/assets-for-api-docs/assets/animation/curve_elastic_in.mp4}
  class ElasticInCurve extends Curve {
    /// Creates an elastic-in curve.
    ///
  