is , by itself , deserving of discussion . 
(ROOT (S (VP (VBZ is) (, ,) (PP (IN by) (NP (PRP itself))) (, ,) (ADJP (NN deserving) (PP (IN of) (NP (NN discussion))))) (. .)))
(ROOT (S (VP (VBZ ) (, ) (PP (IN ) (NP (PRP ))) (, ) (ADJP (NN ) (PP (IN ) (NP (NN ))))) (. )))