<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def list_actions(self):
 """ Returns the registered actions. :return: Actions list. :rtype: list """


        actions = []
        for path, actionName, action in self:
            actions.append(self.__namespace_splitter.join(itertools.chain(path, (actionName,))))
        return sorted(actions)