package docs.stream.cookbook import akka.NotUsed import akka.stream.ClosedShape import akka.stream.scaladsl._ import akka.stream.testkit._ import akka.util.ByteString class RecipeKeepAlive extends RecipeSpec { "Recipe for injecting keepalive messages" must { "work" in { val keepaliveMessage = ByteString(11) //#inject-keepalive import scala.concurrent.duration._ val injectKeepAlive: Flow[ByteString, ByteString, NotUsed] = Flow[ByteString].keepAlive(1.second, () => keepaliveMessage) //#inject-keepalive // No need to test, this is a built-in stage with proper tests } } }