code: function createNode(lock, callback) {
    var nodePath = utils.join(lock.basePath, lock.lockName);
    var client = lock.client;
  
    client
      .create()
      .creatingParentsIfNeeded()
      .withMode(CreateMode.EPHEMERAL_SEQUENTIAL)
      .forPath(nodePath, callback);
  }
docs: Create lock node.
  
  @private
  @param {Lock} lock Lock instance
  @param {Function} callback Callback function: `(err, nodePath)`