code: function MongoCache(options) {
      options = options || {};
  
      var url = options.url || 'http://localhost/openam-agent',
          expireAfterSeconds = options.expireAfterSeconds || 60,
          collectionName = options.collectionName || 'agentcache';
  
      this.collection = mongodb.MongoClient.connectAsync(url).then(function (db) {
          var collection = db.collection(collectionName);
          return collection.createIndex('timestamp', {expireAfterSeconds: expireAfterSeconds}).then(function () {
              return collection;
          });
      });
  }
docs: Cache implementation for MongoDB
  
  @extends Cache
  
  @param {object} [options] Options
  @param {string} [options.url=http://localhost/openam-agent] MongoDB URL
  @param {number} [options.expireAfterSeconds=60] Expiration time in seconds
  @param {string} [options.collectionName=agentcache] MongoDB collection name
  
  @example
  var mongoCache = new MongoCache({
  url: 'mongodb://db.example.com/mydb',
  expireAfterSeconds: 600,
  collectionName: 'sessions'
  });
  
  @constructor