code: function addToQueue(items, extraParams, targetQueue, cb) {
    if (!items || items.length === 0) {
      return cb();
    }
    var itemsToPush = _.map(items, function(item) {
      return _.extend({}, item, extraParams);
    });
    debug("adding %d items to queue %s", itemsToPush.length, targetQueue.getName());
    targetQueue.addMany(itemsToPush, cb);
  }
docs: Add the given items to the given queue. For each item, also add the given extraParams.
  @param {Array} items the items to add to the queue
  @param {Object} extraParams extra data that should be added to each item
  @param {MongodbQueue} targetQueue the queue to push the messages to
  @param {Function} cb the callback function