public void UnknownFloorException_MustProvideExpectedErrorMessage()
{
string expectedErrorMessage = "Unknown floor value";
Exception ex = new UnknowFloorExecption();
Assert.True(ex.Message.StartsWith(expectedErrorMessage));
}
public void UnknownFloorException_MustBeException()
{
Exception ex = new UnknowFloorExecption();
Assert.NotNull(ex);
}