code: function DiskStore(options) {
      options = options || {};
  
      this.options = extend({
          path: 'cache/',
          ttl: 60,
          maxsize: 0,
          zip: false
      }, options);
  
  
      // check storage directory for existence (or create it)
      if (!fs.existsSync(this.options.path)) {
          fs.mkdirSync(this.options.path);
      }
  
      this.name = 'diskstore';
  
      // current size of the cache
      this.currentsize = 0;
  
      // internal array for informations about the cached files - resists in memory
      this.collection = {};
  
      // fill the cache on startup with already existing files
      if (!options.preventfill) {
  
          this.intializefill(options.fillcallback);
      }
  }
docs: construction of the disk storage