createCanvas(windowWidth,

               windowHeight);

  pen = new Pen(width/2,

                   height/2);

  background("orange");

  stroke("blue");

  pen.moveForward(200);

  pen.turnRight(90);

  pen.moveForward(200);

  pen.turnRight(90);

  pen.moveForward(200);

  pen.turnRight(90);

  pen.moveForward(200);

}