code: function _initStorage(options) {
          var self = this;
          var dbInfo = {
              db: null
          };
  
          if (options) {
              for (var i in options) {
                  dbInfo[i] = options[i];
              }
          }
  
          return new Promise(function(resolve, reject) {
              var openreq = indexedDB.open(dbInfo.name, dbInfo.version);
              openreq.onerror = function() {
                  reject(openreq.error);
              };
              openreq.onupgradeneeded = function() {
                  // First time setup: create an empty object store
                  openreq.result.createObjectStore(dbInfo.storeName);
              };
              openreq.onsuccess = function() {
                  dbInfo.db = openreq.result;
                  self._dbInfo = dbInfo;
                  resolve();
              };
          });
      }
docs: Open the IndexedDB database (automatically creates one if one didn't previously exist), using any options set in the config.