code: function Cache(options) {
      if (typeof (options) !== 'object')
          throw new TypeError('options (object) required');
  
      this._cache = LRU(options.size || 1000);
      this._age = (options.age || 60) * 1000;
  
      var self = this;
      this.__defineGetter__('age', function () { return self._age / 1000; });
      this.__defineSetter__('age', function (a) {
          self._age = a * 1000;
      });
  }
docs: --- API