public bool TryAdd(object instanceOrReplica, out PathString urlPrefix) { if (instanceOrReplica == null) { throw new ArgumentNullException(nameof(instanceOrReplica)); } if (!(instanceOrReplica is IStatelessServiceInstance) && !(instanceOrReplica is IStatefulServiceReplica)) { throw new ArgumentException(null, nameof(instanceOrReplica)); } urlPrefix = UrlPrefix.NewUrlPrefix(); return(ImmutableInterlocked.TryAdd(ref _entries, urlPrefix, instanceOrReplica)); }