public ZkConnection(String zkServers,int sessionTimeOut,String authStr){
  _servers=zkServers;
  _sessionTimeOut=sessionTimeOut;
  _authStr=authStr;
}

public ZkConnection ( String zkServers , int sessionTimeOut , String authStr ) { _servers = zkServers ; _sessionTimeOut = sessionTimeOut ; _authStr = authStr ; }
build a zookeeper connection
