     equals result.x, point.x + x
     equals result.y, point.y + y
 
+  test "#add$", ->
+    p = Point(0, 0)
+
+    p.add$(Point(3, 5))
+
+    equals p.x, 3
+    equals p.y, 5
+
+    p.add$(2, 1)
+
+    equals p.x, 5
+    equals p.y, 6
+
   test "#subtract", ->
     p1 = Point(5, 6)
     p2 = Point(7, 5)


    equals result.x, p1.x + p2.x
    equals result.y, p1.y + p2.y

  test "#add with two arguments", ->
    point = Point(3, 7)


    equals result.x, p1.x - p2.x
    equals result.y, p1.y - p2.y

  test "#subtract$", ->
    p = Point(8, 6)

    p.subtract$(3, 4)

    equals p.x, 5
    equals p.y, 2

  test "#norm", ->
    p = Point(2, 0)
