public static boolean isEmpty(final CharSequence cs) {
        return cs == null || cs.length() == 0;
    }
Determine if it is an empty string

@param cs string
@return whether it is empty
chat2db-server/chat2db-server-web/chat2db-server-web-api/src/main/java/ai/chat2db/server/web/api/util/StringUtils.java