//pass to server for result
    val respStreamObserver = new StreamObserver[SumResponse] { override def onError(t: Throwable): Unit = println(s"error: ${t.getMessage}") override def onCompleted(): Unit = println("Done responding!") override def onNext(value: SumResponse): Unit = println(s"Result: ${value.currentResult}") } //get async stub
    val client = SumManyToOneGrpc.stub(channel) //get request stream observer from server
    val reqStreamObserver = client.addManyToOne(respStreamObserver) List(2,5,8,4,0).map { n => reqStreamObserver.onNext(SumRequest(n)) }

/* * Sums up numbers received from the client and returns the current result after each received request. */ service SumInter { rpc AddInter(stream SumRequest) returns (stream SumResponse) {} }

  class Many2ManyService extends SumInterGrpc.SumInter { override def addInter(responseObserver: StreamObserver[SumResponse]): StreamObserver[SumRequest] =
      new StreamObserver[SumRequest] { val currentSum: AtomicInt = Atomic(0) override def onError(t: Throwable): Unit = println(s"error: ${t.getMessage}") override def onCompleted(): Unit = println("Done requesting!") override def onNext(value: SumRequest): Unit = { responseObserver.onNext(SumResponse(currentSum.addAndGet(value.toAdd))) } } }

    //create stream observer for result stream
    val responseObserver = new StreamObserver[SumResponse] { def onError(t: Throwable): Unit = println(s"ON_ERROR: $t") def onCompleted(): Unit = println("ON_COMPLETED") def onNext(value: SumResponse): Unit = println(s"ON_NEXT: Current sum: ${value.currentResult}") } //get request container
    val requestObserver = client.addInter(responseObserver) scheduler.scheduleWithFixedDelay(0.seconds, 1.seconds) { val toBeAdded = Random.nextInt(11) println(s"Adding number: $toBeAdded") requestObserver.onNext(SumRequest(toBeAdded)) }

addSbtPlugin("com.thesamet" % "sbt-protoc" % "0.99.18") libraryDependencies += "com.thesamet.scalapb" %% "compilerplugin" % "0.7.1"