TestFixtureAttribute (NUnit 2.0)
This is the attribute that marks a class that contains tests and, optionally,
setup or teardown methods.
There are a few restrictions on a class that is used as a test fixture.
It must be a publicly exported type or NUnit will not see it.
It must have a default constructor or NUnit will not be able to construct it.
The constructor should not have any side effects, since NUnit may construct the
class multiple times in the course of a session.
public class SuccessTests