anchor.diff:      this.height: 400,
       List<Color> colors,
       this.onClick}) :
  -      colors = colors == null ? defaultColors : _makeCssColors(colors)
  +      this.colors = (colors == null) ? defaultColors : colors
     {
       var radiusPixels = width < height ? width/2.0 : height/2.0;
       scalePixel = radius / radiusPixels;
  
positive.code:   @override
    bool operator==(other) =>
      other is Complex && real==other.real && imag==other.imag;
  
    @override
    toString() => imag >= 0 ? "${real}+${imag}i" : "${real}${imag}i";
  
negative.code:   final int width;
    final int height;
    final ClickHandler onClick;
    final List<Color> colors;
    double scalePixel;
  
    MandelbrotView({
  