code: function getItem(id) {
    return new Promise((resolve, reject) => {
      return instance.pkgs.then(db => {
        const req = db.transaction(db.name)
          .objectStore(db.name).get(id);
        req.onsuccess = event => resolve(event.target.result);
        req.onerror = event => reject(event);
      });
    });
  }
docs: Get packages by instance ID
  @param {string} id - Package instance ID
  @return {array} data store object