anchor.diff:    /// Returns a new curve that is the reversed inversion of this one.
     /// This is often useful as the reverseCurve of an [Animation].
     ///
  -  /// ![](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_flipped.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_flipped.mp4}
     ///
     /// See also:
     ///
  
positive.code:   /// This is equivalent to the Android `DecelerateInterpolator` class with a unit
    /// factor (the default factor).
    ///
    /// ![](https://flutter.github.io/assets-for-api-docs/assets/animation/curve_decelerate.png)
    static const Curve decelerate = const _DecelerateCurve._();
  
    /// A cubic animation curve that speeds up quickly and ends slowly.
    ///
    /// ![](https://flutter.github.io/assets-for-api-docs/assets/animation/curve_ease.png)
    static const Cubic ease = const Cubic(0.25, 0.1, 0.25, 1.0);
  
    /// A cubic animation curve that starts slowly and ends quickly.
    ///
    /// ![](https://flutter.github.io/assets-for-api-docs/assets/animation/curve_ease_in.png)
    static const Cubic easeIn = const Cubic(0.42, 0.0, 1.0, 1.0);
  
    /// A cubic animation curve that starts quickly and ends slowly.
    ///
    /// ![](https://flutter.github.io/assets-for-api-docs/assets/animation/curve_ease_out.png)
    static const Cubic easeOut = const Cubic(0.0, 0.0, 0.58, 1.0);
  
    /// A cubic animation curve that starts slowly, speeds up, and then and ends slowly.
    ///
    /// ![](https://flutter.github.io/assets-for-api-docs/assets/animation/curve_ease_in_out.png)
    static const Cubic easeInOut = const Cubic(0.42, 0.0, 0.58, 1.0);
  
    /// A curve that starts quickly and eases into its final position.
  
negative.code: /// The curve rises linearly from 0.0 to 1.0 and then falls discontinuously back
  /// to 0.0 each iteration.
  ///
  /// {@animation 464 192 https://flutter.github.io/assets-for-api-docs/assets/animation/curve_sawtooth.mp4}
  class SawTooth extends Curve {
    /// Creates a sawtooth curve.
    ///
  