public void TestNull() { // ReSharper disable ExpressionIsAlwaysNull // Define variables and constants object nonNullObj = new object(); object nullObj = null; int? nonNullInt = 3; int? nullInt = null; // Set up context // Execute Assure.Null(nullObj); try { Assure.Null(nonNullObj); Assert.Fail(); // Should throw the exception } catch (AssuranceFailedException) { } Assure.Null(nullInt); try { Assure.Null(nonNullInt); Assert.Fail(); // Should throw the exception } catch (AssuranceFailedException) { } // Assert outcome // ReSharper restore ExpressionIsAlwaysNull }