anchor.diff:      // We build a path for the notch from 3 segments:
       // Segment A - a Bezier curve from the host's top edge to segment B.
       // Segment B - an arc with radius notchRadius.
  -    // Segment C - a Bezier curver from segment B back to the host's top edge.
  +    // Segment C - a Bezier curve from segment B back to the host's top edge.
       //
       // A detailed explanation and the derivation of the formulas below is
       // available at: https://goo.gl/Ufzrqn
  
positive.code: 
  /// A rectangle with a smooth circular notch.
  class CircularNotchedRectangle implements NotchedShape {
    /// Creates a `CircularNotchedRectangle`.
    ///
    /// The same object can be used to create multiple shapes.
    const CircularNotchedRectangle();
  
negative.code: ///
  /// Typically used as the outline of a 'host' widget to make a notch that
  /// accommodates a 'guest' widget. e.g the [BottomAppBar] may have a notch to
  /// accommodate the [FloatingActionButton].
  
  /// See also: [ShapeBorder], which defines a shaped border without a dynamic
  /// notch.
  