Add hash->ordered-list.

graph.rkt

@@ -168,6 +168,12 @@
   ;; whether the results make sense.
   (require typed/rackunit)
 
+  ;; TODO: Submit an update to hash->list in Racket and then remove
+  ;; this function.
+  (: hash->ordered-list (All (a b) (-> (HashTable a b) (Listof (Pairof a b)))))
+  (define (hash->ordered-list h)
+    (hash-map h (inst cons a b) #t))
+
   (test-case "1 Generic Graph Interface"
     (define g (directed-graph '((a b) (b c))))
     (check-false (has-edge? g 'a 'c))