anchor.diff:                    bottom: 0.0,
                     child: new CustomPaint(
                       painter: new _RadialPainter(
  -                      circles: _circles.toList()
  +                      circles: _circles.toList(),
  +                      bottomNavMaxWidth: _maxWidth,
                       ),
                     ),
                   ),
  
positive.code:       final Paint paint = new Paint()..color = circle.color;
        final Rect rect = new Rect.fromLTWH(0.0, 0.0, size.width, size.height);
        canvas.clipRect(rect);
        canvas.drawCircle(
          circle.offset.withinRect(rect),
          radiusTween.lerp(circle.animation.value),
          paint
        );
  
negative.code: 
  class _RadialPainter extends CustomPainter {
    _RadialPainter({
      this.circles,
      this.bottomNavMaxWidth,
    });
  
    final List<_Circle> circles;
    final double bottomNavMaxWidth;
  
    // Computes the maximum radius attainable such that at least one of the
    // bounding rectangle's corners touches the egde of the circle. Drawing a
  