anchor.diff:  
   typedef double Easing(double t);
   
  -
   final Map<String, Easing> MapStringToEasing = {
     "Cosine": EasingCosine,
     "Sine": EasingSine,
  
positive.code:   "Linear": EasingLinear,
  };
  
  List<VM.Vector2> BevelSupportPoints(double width, double height, int nSupports,
      {Easing widthEasing = EasingCosine, Easing heightEasing = EasingSine}) {
    // out[0]
  
negative.code:   return out;
  }
  
  // Merges a two-dimensional contour (plus corresponding gradient) with
  // a two-dimension bevel support.
  // the contour remains in the x,y plane but is replicated at different
  // z-levels based on the y-coordinate of the bevel support.
  // At each level the contour is extended based on the gradient and the supports
  // x-coordinate.
  // Typically supports[0] == (0,0) which means thet contour will appear
  // a level z=0 unchanged.
  List<List<VM.Vector3>> BevelStrips(List<VM.Vector2> contour,
      List<VM.Vector2> gradient, List<VM.Vector2> supports, VM.Matrix3 m) {
    assert(contour.length == gradient.length);
  