'Gets back a previously saved action. This method can return None if the action
was saved since too much time (this case should be handled in a smart way).
:param key: The key given by save_action()
:type key: integer
:return: The saved action or None.
:rtype: anything'

def get_action(self, key):

    saved_actions = self.get('saved_actions', {})
    return saved_actions.get('actions', {}).get(key)
