public void GetAllAccountClasses_ShouldReturnAllValidValues_UnderAllConditions() { // Arrange & Act AccountClass[] output = CUT.GetAllAccountClasses().ToArray(); // Assert output.ShouldNotBeNull(); output.ShouldNotBeEmpty(); output.ShouldContain(AccountClass.Residential); output.ShouldContain(AccountClass.SmallCommercial); output.ShouldContain(AccountClass.LargeCommercial); }