Private class data

namespace Private_class_data
{
    class Program
    {
        static void Main(string[] args)
        {
            var radius = new double();
            var color = new Color();
            var origin = new Point();
 
            var circle_before = new before.Circle(radius, color, origin);
            var circle_after = new after.Circle(radius, color, origin);
        }
    }
 
    class Color
    {
    }
 
    class Graphics
    {
    }
 
    class Point
    {
    }
 
 
}
 
namespace Private_class_data.before
{
    class Circle
    {
        private double radius;
        private Color color;
        private Point origin;
        public Circle(double radius, Color color, Point origin)
        {
            this.radius = radius;
            this.color = color;
            this.origin = origin;
        }
        public double Circumference
        {
            get { return 2 * Math.PI * this.radius; }
        }
        public double Diameter
        {
            get { return 2 * this.radius; }
        }
        public void Draw(Graphics graphics)
        {
            //...
        }
 
    }
}
 
namespace Private_class_data.after
{
    class CircleData
    {
        private double radius;
        private Color color;
        private Point origin;
 
        public CircleData(double radius, Color color, Point origin)
        {
            this.radius = radius;
            this.color = color;
            this.origin = origin;
        }
 
        public double Radius
        {
            get { return this.radius; }
        }
        public Color Color
        {
            get { return this.color; }
        }
        public Point Origin
        {
            get { return this.origin; }
        }
 
    }
 
    class Circle
    {
        private CircleData circleData;
 
        public Circle(double radius, Color color, Point origin)
        {
            circleData = new CircleData(radius, color, origin);
        }
        public double Circumference
        {
            get { return 2 * Math.PI * this.circleData.Radius; }
        }
        public double Diameter
        {
            get { return 2 * this.circleData.Radius; }
        }
        public void Draw(Graphics graphics)
        {
            //...
        }
 
    }
}