impl = createCachingExecChain(mockBackend, new BasicHttpCache(), CacheConfig.DEFAULT);
final HttpRequestWrapper req1 = HttpRequestWrapper.wrap(new HttpGet(
"http://foo.example.com/"));
final HttpRequestWrapper req2 = HttpRequestWrapper.wrap(new HttpGet(
"http://foo.example.com/"));
req2.addHeader("If-Modified-Since", DateUtils.formatDate(now));
final HttpResponse resp1 = new BasicHttpResponse(HttpVersion.HTTP_1_1, HttpStatus.SC_OK,
"OK");
resp1.setEntity(HttpTestUtils.makeBody(128));
resp1.setHeader("Content-Length", "128");
resp1.setHeader("ETag", "\"etag\"");