private static Flow <TIn, TOut, NotUsed> Balancer <TIn, TOut>(Flow <TIn, TOut, NotUsed> worker, int workerCount)
{
return(Flow.FromGraph(GraphDsl.Create(b =>
{
var balancer = b.Add(new Balance <TIn>(workerCount, waitForAllDownstreams: true));
var merge = b.Add(new Merge <TOut>(workerCount));
for (var i = 0; i < workerCount; i++)
{
b.From(balancer).Via(worker.Async()).To(merge);
}
return new FlowShape <TIn, TOut>(balancer.In, merge.Out);
})));
}