@Override
            public String getUUID() {
                String uuid = Site.this.getDomain();
                if (uuid == null) {
                    uuid = UUID.randomUUID().toString();
                }
                return uuid;
            }
Downloader is supposed to store response cookie.
Disable it to ignore all cookie fields and stay clean.
Warning: Set cookie will still NOT work if disableCookieManagement is true.
@param disableCookieManagement disableCookieManagement
@return this
webmagic-core/src/main/java/us/codecraft/webmagic/Site.java