.url("https://publicobject.com/helloworld.txt")
        .build();

    try (Response response = client.newCall(request).execute()) {
      if (!response.isSuccessful()) {
        Headers responseHeaders = response.headers();
        for (int i = 0; i < responseHeaders.size(); i++) {
          System.out.println(responseHeaders.name(i) + ": " + responseHeaders.value(i));
        }

        .build();

    try (Response response = client.newCall(request).execute()) {
      if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);

      Headers responseHeaders = response.headers();
      for (int i = 0; i < responseHeaders.size(); i++) {
        System.out.println(responseHeaders.name(i) + ": " + responseHeaders.value(i));
      }

      System.out.println(response.body().string());

      logger.info(String.format("Sending request %s on %s%n%s",
          request.url(), chain.connection(), request.headers()));
      Response response = chain.proceed(request);

      long t2 = System.nanoTime();
      logger.info(String.format("Received response for %s in %.1fms%n%s",
          request.url(), (t2 - t1) / 1e6d, response.headers()));
      return response;
    }
  }

  public static void main(String... args) throws Exception {

      System.out.println(response.request().header("Date"));
    }
  }

  static class CurrentDateInterceptor implements Interceptor {
    @Override public Response intercept(Chain chain) throws IOException {
      Request request = chain.request();
      Headers newHeaders = request.headers()
          .newBuilder()
          .add("Date", new Date())
          .build();

            RequestBody.create(
                new File("docs/images/logo-square.png"),
                MEDIA_TYPE_PNG))
        .build();

    Request request = new Request.Builder()
        .header("Authorization", "Client-ID " + IMGUR_CLIENT_ID)
        .url("https://api.imgur.com/3/image")
        .post(requestBody)
        .build();

    try (Response response = client.newCall(request).execute()) {

      if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);

      System.out.println("Server: " + response.header("Server"));
      System.out.println("Date: " + response.header("Date"));
      System.out.println("Vary: " + response.headers("Vary"));
    }
  }

  public static void main(String... args) throws Exception {
    new AccessHeaders().run();
  }

        try (ResponseBody responseBody = response.body()) {
          if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);

          Headers responseHeaders = response.headers();
          for (int i = 0, size = responseHeaders.size(); i < size; i++) {
            System.out.println(responseHeaders.name(i) + ": " + responseHeaders.value(i));
          }

    }

    @Override public Response intercept(Chain chain) throws IOException {
      Request request = chain.request();
      if (request.url().host().equals(host)) {
        request = request.newBuilder()
            .header("Authorization", credentials)
            .build();
      }
      return chain.proceed(request);
    }
  }

          + ")") : "(cache)";
      int responseCode = response.code();

      System.out.printf("%03d: %s %s%n", responseCode, url, responseSource);

      String contentType = response.header("Content-Type");
      if (responseCode != 200 || contentType == null) {
        return;
      }

      MediaType mediaType = MediaType.parse(contentType);

public final class RewriteResponseCacheControl {
  /** Dangerous interceptor that rewrites the server's cache-control header. */
  private static final Interceptor REWRITE_CACHE_CONTROL_INTERCEPTOR = chain -> {
    Response originalResponse = chain.proceed(chain.request());
    return originalResponse.newBuilder()
        .header("Cache-Control", "max-age=60")
        .build();
  };

  private final OkHttpClient client;