(pvalues & exprs)
Returns a lazy sequence of the values of the exprs, which are evaluated in parallel
;; expressions are calculated in parallel
user=> (pvalues (expensive-calc-1) (expensive-calc-2))
(2330 122)
;; pvalues is implemented using Clojure futures. See examples for 'future'
;; for discussion of an undesirable 1-minute wait that can occur before
;; your standalone Clojure program exits if you do not use shutdown-agents.