Get action needs and excludes from cache.

        .. note:: It returns the action if a cache system is defined.

        :param action_key: The unique action name.
        :returns: The action stored in cache or ``None``.

def get_action_cache(self, action_key):
        """Get action needs and excludes from cache.

        .. note:: It returns the action if a cache system is defined.

        :param action_key: The unique action name.
        :returns: The action stored in cache or ``None``.
        """
        data = None
        if self.cache:
            data = self.cache.get(
                self.app.config['ACCESS_ACTION_CACHE_PREFIX'] +
                action_key
            )
        return data