+ """Running action implementation.
+
+ To implement new actions,
+
+ - Add a new element/class pair to parser.ActionDef.CONSTRUCTORS.
+ It should support FromXML, __getstate__, and __setstate__.
+ - Subclass impl.Action and override the 'handle' method to handle
+ your custom action type.
+ - Pass the impl.Bullet constructor your Action subclass when
+ creating your root Bullet.
+
+ Or, for very simple actions, add it to the Action.CUSTOM
+ dictionary. The key should be the type of the action and the
+ value a 3-ary callable that recieves the Action instance, the
+ owner, and a list to append created bullets to.
+ """
+
+ CUSTOM = {}