How to implement Ping Pong based keep alive in akka-http 10.0.10 and stream

Hi, How can I implement Ping Pong using akka-http 10.0.10 and akka-stream. For some reason it not possible as of now to upgrade akka and akka-http.

I referred!msg/akka-user/GCim2YNa7w8/h62R_NqUEAAJ and tries but could not achieve. A simple actor & Flow based implementation to include Ping Frame would be a life saver.

Thank you,