func SetMulti(c context.Context, item []*Item) error {
	return set(c, item, nil, pb.MemcacheSetRequest_SET)
}
func SetMulti(c context.Context, item []*Item) error {
	return set(c, item, nil, pb.MemcacheSetRequest_SET)
}
// SetMulti is a batch version of Set.
// appengine.MultiError may be returned.