https://doc.akka.io/api/akka-core/current/akka/stream/scaladsl/GraphDSL$$Implicits$$BidiFlowShapeArrow.html
Akka 2.10.17 - akka.stream.scaladsl.GraphDSL.Implicits.BidiFlowShapeArrow
Akka 2.10.17 - akka.stream.scaladsl.GraphDSL.Implicits.BidiFlowShapeArrow
akkastreamscaladslgraphdslimplicits