@Test
public void testMesosStreamIdNotPresentWhenNull() throws Exception {

    final Func1<String, Observable<HttpClientRequest<ByteBuf>>> createPost = MesosClient.curryCreatePost(
        URI.create("http://localhost:12345/api/v1/scheduler"),
        StringMessageCodec.UTF8_STRING,
        StringMessageCodec.UTF8_STRING,
        new UserAgent(
            literal("testing", "latest")
        ),
        new AtomicReference<>(null)
    );
    final HttpClientRequest<ByteBuf> request = createPost.call("something")
        .toBlocking()
        .first();
    final Map<String, String> headers = headersToMap(request.getHeaders());
    assertThat(headers).doesNotContainKeys("Mesos-Stream-Id");
}