lib/zookeeper.js
function writeClientConfig(client, clientId, configs, callback) {
  debug('writeClientConfig: "%s", %j', clientId, configs);
  updateEntityConfig(client, getClientConfigPath(clientId), configs, callback);
}
function writeClientConfig(client, clientId, configs, callback) {
  debug('writeClientConfig: "%s", %j', clientId, configs);
  updateEntityConfig(client, getClientConfigPath(clientId), configs, callback);
}
function writeClientConfig ( client , clientId , configs , callback ) { debug ( 'writeClientConfig: "%s", %j' , clientId , configs ) ; updateEntityConfig ( client , getClientConfigPath ( clientId ) , configs , callback ) ; }
Write out the client config to zk, if there is any

@param {ZkClient} client
@param {String} clientId
@param {Object} configs
@param {Function} callback
Write out the client config to zk if there is any