+#
+# Unlike standard HashMap, MultiHashMap provides a new
+# empty array on the first access on a unknown key.
+#
+# var m = new MultiHashMap[String, Char]
+# assert not m.has_key("four")
+# m["four"].add('i')
+# m["four"].add('i')
+# m["four"].add('i')
+# m["four"].add('i')
+# assert m.has_key("four")
+# assert m["four"] == ['i', 'i', 'i', 'i']
+# assert m["zzz"] == new Array[Char]