SetUpTearDownItem
SetUpTearDownItem holds the setup and teardown methods
            for a single level of the inheritance hierarchy.
            
                
Returns true if this level has any methods at all.
             This flag is used to discard levels that do nothing.
            
public SetUpTearDownItem(IList<IMethodInfo> setUpMethods, IList<IMethodInfo> tearDownMethods, IMethodValidator methodValidator = null)
Construct a SetUpTearDownNode
            
Run SetUp on this level.
            
Run TearDown for this level.