what should have been a painless time-killer becomes instead a grating endurance test . 
(ROOT (S (SBAR (WHNP (WP what)) (S (VP (MD should) (VP (VB have) (VP (VBN been) (NP (DT a) (JJ painless) (NN time) (HYPH -) (NN killer))))))) (VP (VBZ becomes) (ADVP (RB instead)) (NP (DT a) (VBG grating) (NN endurance) (NN test))) (. .)))
(ROOT (S (SBAR (WHNP (WP )) (S (VP (MD ) (VP (VB ) (VP (VBN ) (NP (DT ) (JJ ) (NN ) (HYPH ) (NN ))))))) (VP (VBZ ) (ADVP (RB )) (NP (DT ) (VBG ) (NN ) (NN ))) (. )))