public void ShouldInitialiseTheLawnAsRectangle()
        {
            LawnInitialiser.Init("5 15");

            Assert.That(Lawn.Height, Is.EqualTo(5));
            Assert.That(Lawn.Width, Is.EqualTo(15));
        }
 public void ShouldThrowIfInvalidInput()
 {
     Assert.Throws <InvalidInputException>(() => LawnInitialiser.Init("5"));
     Assert.Throws <InvalidInputException>(() => LawnInitialiser.Init("x x"));
 }