-# A map implemented with a hash table.
-# Keys of such a map cannot be null and require a working `hash` method
-class HashMap[K: Object, V]
+# A `Map` implemented with a hash table.
+#
+# ~~~
+# var map = new HashMap[nullable String, Int]
+# map[null] = 0
+# map["one"] = 1
+# map["two"] = 2
+#
+# assert map[null] == 0
+# assert map["one"] == 1
+# assert map.keys.has("two")
+# assert map.values.length == 3
+# ~~~
+class HashMap[K, V]