crawlerContext.intervalController.delay(IntervalController.WAIT_NEW_URL);
                }
            }
        } catch (final Throwable t) {
            log(logHelper, LogType.SYSTEM_ERROR, t);
        } finally {
            // remove crawlerContext from thread
            CrawlingParameterUtil.setCrawlerContext(null);
            CrawlingParameterUtil.setUrlQueueService(null);

        /** Successful response status. */
        OK(0),
        /** Bad request status indicating client error. */
        BAD_REQUEST(1),
        /** System error status indicating server error. */
        SYSTEM_ERROR(2),
        /** Unauthorized status indicating authentication failure. */
        UNAUTHORIZED(3),
        /** General failure status. */
        FAILED(9);

        private final int id;