is an object lesson in period filmmaking 
(ROOT (S (VP (VBZ is) (NP (NP (DT an) (NN object) (NN lesson)) (PP (IN in) (NP (NN period) (NN filmmaking)))))))
(ROOT (S (VP (VBZ ) (NP (NP (DT ) (NN ) (NN )) (PP (IN ) (NP (NN ) (NN )))))))