(defn select-keys
"Returns a map containing only those entries in map whose key is in keys"
{:added "1.0"
:static true}
[map keyseq]
(loop [ret {} keys (seq keyseq)]
(if keys
(let [entry (. clojure.lang.RT (find map (first keys)))]
(recur
(if entry
(conj ret entry)
ret)
(next keys)))
(with-meta ret (meta map)))))