(with-random-access-reader "/Users/angerman/upps.data.model"
  (println (next-line)) ;; first line
  (println (next-line)) ;; second line
  (save-excursion
   (println (subs (last (lazy-rest)) 0 20))) ;; last line's first 20 char
  (println (next-line)) ;; third line
  (println (subs (last (lazy-rest)) 0 20))) ;; last lines first 20 char