fix .transduce method to support new protocol (see #78)
fix .transduce method to support new protocol (see #78)

AyaMorisawa/kefir,AgentME/kefir,pixelpicosean/kefir,elsehow/kefir,kelsadita/kefir,lautis/kefir,kelsadita/kefir,hsavit1/kefir,pixelpicosean/kefir,AgentME/kefir,hsavit1/kefir,elsehow/kefir,lautis/kefir,AyaMorisawa/kefir