val f = { channel: Channel =>
      requests: List[Req] =>
        requests.foreach { request =>
          completeObserver(ClientCalls.asyncBidiStreamingCall(channel.newCall(method, CallOptions.DEFAULT), responseObserver))(Try(request))
        }

def completeObserver[T](observer: StreamObserver[T])(t: Try[T]): Unit =
    t.map(observer.onNext) match {
      case scala.util.Success(_) =>
        observer.onCompleted()
      case scala.util.Failure(s: StatusException) =>
        observer.onError(s)
      case scala.util.Failure(s: StatusRuntimeException) =>
        observer.onError(s)
      case scala.util.Failure(e) =>
        observer.onError(
          Status.INTERNAL.withDescription(e.getMessage).withCause(e).asException()
        )
    }

  val requests: List[StreamingRecognizeRequest] =
    StreamingRecognizeRequest()
      .withStreamingConfig(streamingConfig) +: byteArray
      .grouped(1024)
      .map(x => StreamingRecognizeRequest().withAudioContent(ByteString.copyFrom(x)))
      .toList