Akka Streams - Understanding the MergeHub and BroadcastHub

I am working on a requirement where we need to create Flows at runtime. Naturally we selected the Graph DSL for this and also since we needed fan-in and fan-out. As I understand from the documentation - https://doc.akka.io/docs/akka/current/stream/stream-dynamic.html#dynamic-fan-in-and-fan-out-with-mergehub-broadcasthub-and-partitionhub ,that we should be using MergeHub and BroadcastHub. However, I did not find much code examples that I can work with. Is there any place/project where I can understand how to deal with fan-in/fan-out for dynamically created flows?

One blog post comes to mind from the top of my head:


It mentions older dependencies, but the usage of the MergeHub and BroadcastHub is still the same.