public void SwapExample()
{
var vector1 = new Vector2D(1, 2);
var vector2 = new Vector2D(3, 4);
vector1.Swap(vector2);
Assert.AreEqual(3, vector1.X);
Assert.AreEqual(4, vector1.Y);
Assert.AreEqual(1, vector2.X);
Assert.AreEqual(2, vector2.Y);
}