is an intelligent , realistic portrayal of testing boundaries . 
(ROOT (S (VP (VBZ is) (NP (NP (DT an) (JJ intelligent) (, ,) (JJ realistic) (NN portrayal)) (PP (IN of) (NP (NN testing) (NNS boundaries))))) (. .)))
(ROOT (S (VP (VBZ ) (NP (NP (DT ) (JJ ) (, ) (JJ ) (NN )) (PP (IN ) (NP (NN ) (NNS ))))) (. )))