code: function CouchDBCache(options) {
      var self = this;
      options = options || {};
  
      this.expireAfterSeconds = options.expireAfterSeconds || 60;
  
      this.connection = Promise.resolve()
          .then(function () {
              return options.auth ? this.auth(options.auth.username, options.auth.password) : null;
          })
          .then(function (cookie) {
              return nano({
                  url: options.url || (options.protocol + '://' + options.host + ':' + options.port),
                  cookie: cookie
              });
          });
  
      // create database if it doesn't exist
      this.db = this.connection.then(function (connection) {
          var dbName = options.db || 'openamagent';
          return Promise.promisify(connection.db.create.bind(connection.db))(dbName)
              .catch(function () {
                  // ignore
              })
              .then(function () {
                  return connection.use(dbName);
              });
      });
  }
docs: Cache implementation for CouchDB
  
  @extends Cache
  
  @param {object} [options] Options
  @param {string} [options.url] CouchDB base URL (or use protocol + host + port)
  @param {string} [options.protocol=http] CouchDB protocol (http|https)
  @param {string} [options.host=http://localhost] CouchDB host
  @param {string} [options.port=5984] CouchDB port
  @param {string} [options.db=openamagent] CouchDB database name
  @param {object} [options.auth] CouchDB auth credentials
  @param {string} [options.auth.username] CouchDB user name
  @param {string} [options.auth.password] CouchDB password
  @param {number} [options.expireAfterSeconds=60] Expiration time in seconds
  
  @example
  var couchDBCache = new CouchDBCache({
  host: 'db.example.com',
  port: 5984,
  auth: {
  username: 'admin',
  password: 'secret123'
  },
  expireAfterSeconds: 600
  });
  
  @constructor