public String prefix(final String str) {
        return this.toString() + " " + str;
    }
Adds this instance's identifier as a prefix to the passed <code>str</code>

@param str String to amend.
@return A new string with this instance's identifier as prefix
inlong-tubemq/tubemq-server/src/main/java/org/apache/inlong/tubemq/server/common/zookeeper/ZooKeeperWatcher.java