How to use the ring.func.base.StorageMixin function in ring

return self.backend.touch(key, expire)

    @asyncio.coroutine
    def get_many_values(self, keys):
        values = yield from self.backend.multi_get(*keys)
        return [v if v is not None else fbase.NotFound for v in values]

    def set_many_values(self, keys, values, expire):
        raise NotImplementedError("aiomcache doesn't support set_multi.")

    def delete_many_values(self, keys):
        raise NotImplementedError("aiomcache doesn't support delete_multi.")


class AioredisStorage(
        CommonMixinStorage, fbase.StorageMixin, BulkStorageMixin):
    """Storage implementation for :class:`aioredis.Redis`."""

    @asyncio.coroutine
    def _get_backend(self):
        backend = yield from self.backend
        return backend

    @asyncio.coroutine
    def get_value(self, key):
        backend = yield from self._get_backend()
        value = yield from backend.get(key)
        if value is None:
            raise fbase.NotFound
        return value

    @asyncio.coroutine

"""Delete values for the given keys."""
        return self.delete_many_values(keys)

    def has_many(self, keys):
        """Check and return existences for the given keys."""
        return self.has_many_values(keys)

    def touch_many(self, keys, expire=Ellipsis):
        """Touch values for the given keys."""
        if expire is Ellipsis:
            expire = self.rope.config.expire_default
        return self.touch_many_values(keys, expire)


class AiomcacheStorage(
        CommonMixinStorage, fbase.StorageMixin, BulkStorageMixin):
    """Storage implementation for :class:`aiomcache.Client`."""

    @asyncio.coroutine
    def get_value(self, key):
        value = yield from self.backend.get(key)
        if value is None:
            raise fbase.NotFound
        return value

    def set_value(self, key, value, expire):
        return self.backend.set(key, value, expire)

    def delete_value(self, key):
        return self.backend.delete(key)

    def touch_value(self, key, expire):