void () { // see http://ru.onlinemschool.com/math/library/vector/add_subtract/ assertEquals(Vector.create(5, 10), Vector.create(1, 2).plus(Vector.create(4, 8))); assertEquals(Vector.create(5, 10, 6), Vector.create(1, 2, 5).plus(Vector.create(4, 8, 1))); assertEquals(Vector.create(5, 10, 6, -11), Vector.create(1, 2, 5, 9).plus(Vector.create(4, 8, 1, -20))); }