code: public void set(double x, double y, double radius) {
          this.x = x;
          this.y = y;
          this.width = radius * 2.0;
          this.height = radius * 2.0;
      }
docs: Sets x,y-coordinate and radius.
  
  @param x The x-coordinate of the center of the Ellipse.
  @param y The y-coordinate of the center of the Ellipse.
  @param radius The radius of the Ellipse.