public void AddInPlace_IfThisIsNull_ThrowArgumentNullException() { double[][] target = null; var other = new[] { new[] { 1.0, 2.0 }, new[] { 3.0, 4.0 } }; // ReSharper disable once ExpressionIsAlwaysNull Action action = () => target.AddInPlace(other); action.ShouldThrow <ArgumentNullException>() .Where(e => e.ParamName == "target"); }