private NettyTransport startNettyTransport(Settings settings, ThreadPool threadPool) {
    BigArrays bigArrays =
        new MockBigArrays(
            new PageCacheRecycler(settings, threadPool), new NoneCircuitBreakerService());

    NettyTransport nettyTransport =
        new NettyTransport(
            settings,
            threadPool,
            new NetworkService(settings),
            bigArrays,
            Version.CURRENT,
            new NamedWriteableRegistry());
    nettyTransport.start();

    assertThat(nettyTransport.lifecycleState(), is(Lifecycle.State.STARTED));
    return nettyTransport;
  }