dedup across files

;; one.clj
(ns my.one)
(my-atom (atom {}))
(swap! my-atom assoc :id 1)
(defn shorthand-get-id []
  (:id @my-atom))

;; two.clj
(ns my.two)
(my-atom (atom {}))
(swap! my-atom assoc :id 2)
(defn shorthand-get-id []
  (:id @my-atom))

;; core.clj
(ns my.core
  (:require [my.one :as one]
            [my.two :as two]))
;; how to not rewrite "shorthand-get-id" in each of
;; one.clj and two.clj???
(defn main []
  (prn (str "one's id " (one/shorthand-get-id) ", "
            "two's id " (two/shorthand-get-id))))