code: private void goingAway(Status status) {
      lifecycleManager.notifyShutdown(status);
      final Status goAwayStatus = lifecycleManager.getShutdownStatus();
      final int lastKnownStream = connection().local().lastStreamKnownByPeer();
      try {
        connection().forEachActiveStream(new Http2StreamVisitor() {
          @Override
          public boolean visit(Http2Stream stream) throws Http2Exception {
            if (stream.id() > lastKnownStream) {
              NettyClientStream.TransportState clientStream = clientStream(stream);
              if (clientStream != null) {
                clientStream.transportReportStatus(
                    goAwayStatus, RpcProgress.REFUSED, false, new Metadata());
              }
              stream.close();
            }
            return true;
          }
        });
      } catch (Http2Exception e) {
        throw new RuntimeException(e);
      }
    }
docs: Handler for a GOAWAY being received. Fails any streams created after the
  last known stream.