code: public static void addKeepAliveHeaders(Map<String, List<String>> headers) {
          StringUtilities.addValueToHeader(headers, "Keep-Alive",
                  HttpProxyConstants.DEFAULT_KEEP_ALIVE_TIME, true);
          StringUtilities.addValueToHeader(headers, "Proxy-Connection",
                  "keep-Alive", true);
      }
docs: Try to force proxy connection to be kept alive.
  
  @param headers the request headers