// A very simple class that defines a cartesian point, and has a translate
// method and a constructor

public class Point3 {
    int x;    // an "instance variable" defining the point's x value
    int y;    // an "instance variable" defining the point's y value

    // a constructor method for a Point object
    public Point3(int x, int y) {
        this.x = x;
        this.y = y;
    }

    // this method translates the point by (dx, dy)
    public void translate(int dx, int dy) {
        this.x += dx;   // "this" is a reference to the object instance
        this.y += dy;   // whose translate method was invoked
    }
}