------------------------- clojure.core/map ([f coll] [f c1 c2] [f c1 c2 c3] [f c1 c2 c3 & colls])   Returns a lazy sequence consisting of the result of applying f to the   set of first items of each coll, followed by applying f to the set   of second items in each coll, until any one of the colls is   exhausted.  Any remaining items in other colls are ignored. Function   f should accept number-of-colls arguments.  nil