(PECL zookeeper >= 0.1.0)
Zookeeper::setWatcher — Set a watcher function.
watcher_cbA watch will be set at the server to notify the client if the node changes.
Başarı durumunda TRUE, başarısızlık durumunda FALSE döner.
This method emits PHP error/warning when parameters count or types are wrong or fail to set watcher.