code: @Test public void responseCacheRequestHeaders() throws IOException, URISyntaxException {
    server.enqueue(new MockResponse().setBody("ABC"));
    server.play();
    final AtomicReference<Request> requestRef=new AtomicReference<Request>();
    client.setOkResponseCache(new AbstractOkResponseCache(){
      @Override public Response get(    Request request) throws IOException {
        requestRef.set(request);
        return null;
      }
    }
  );
    URL url=server.getUrl("/");
    URLConnection urlConnection=openConnection(url);
    urlConnection.addRequestProperty("A","android");
    readAscii(urlConnection);
    assertEquals(Arrays.asList("android"),requestRef.get().headers("A"));
  }
  