/**
 * CSE 331 16sp section 3
 * checkRep demo.
 */

class Point {
  double x, y;
	
  public Point(double x, double y) {
    this.x = x;
    this.y = y;
  }
}

class Circle {
  private Point center;
  private double radius;
	
  public Circle(Point center, double radius) {
    this.center = center;
    this.radius = radius;
		
    checkRep();
  }
	
  public void checkRep() {
    assert this.center != null;
    assert this.radius > 0;
  }
}


public class CheckRepDemo {

  public static void main(String[] args) {
    // create a new circle
    new Circle(new Point(1, 1), 10);
		
    // create an invalid circle
    Point p = null;
    new Circle(p, 10);
		
    // create another invalid circle
    new Circle(new Point(1, 1), -44.22323);
		
    System.out.println("All good to go!");
  }

}