by the time it 's done with us , 
(ROOT (S (PP (IN by) (NP (NP (DT the) (NN time)) (SBAR (S (NP (PRP it)) (VP (VBZ 's) (VP (VBN done) (PP (IN with) (NP (PRP us))))))))) (, ,)))
(ROOT (S (PP (IN ) (NP (NP (DT ) (NN )) (SBAR (S (NP (PRP )) (VP (VBZ ) (VP (VBN ) (PP (IN ) (NP (PRP ))))))))) (, )))