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

public class Point2 {
    int x;    // an "instance variable" defining the point's x value
    int y;    // an "instance variable" defining the point's y value

    // 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
    }
}