private Delta DeltaFromProto(Akka.Cluster.PubSub.Serializers.Proto.Delta delta)
{
return new Delta(delta.BucketsList.Select(b =>
{
var content = b.ContentList.Aggregate(ImmutableDictionary<string, ValueHolder>.Empty, (map, entry) =>
map.Add(entry.Key, new ValueHolder(entry.Version, entry.HasRef ? ResolveActorRef(entry.Ref) : null)));
return new Bucket(AddressFromProto(b.Owner), b.Version, content);
}).ToArray());
}