private String getExtInfo(ProfileEvent event) {
        if (event.getHeaders().size() > 0) {
            StringBuilder sBuilder = new StringBuilder();
            for (Map.Entry<String, String> extInfo : event.getHeaders().entrySet()) {
                String key = extInfo.getKey();
                String value = extInfo.getValue();
                sBuilder.append(key).append('=').append(value).append('&');
            }
            return sBuilder.substring(0, sBuilder.length() - 1);
        }
        return "";
    }
Parse event to {@literal List<LogItem>} format.

@param context Context of CLS sink.
@param event Event to be pares to {@literal List<LogItem>}
@return Prepared data structure to send.
inlong-sort-standalone/sort-standalone-source/src/main/java/org/apache/inlong/sort/standalone/sink/cls/DefaultEvent2LogItemHandler.java