Clojure vary-meta

(ns clojure.examples.example
   (:gen-class))
(defn Example []
   (def my-map (with-meta [1 2 3] {:prop values}))
   (println (meta my-map))
   (def new-map (vary-meta my-map assoc :newprop new values))
   (println (meta new-map)))
(Example)