code: function clear$1(callback) {
      var self = this;
  
      var promise = new Promise$1(function (resolve, reject) {
          self.ready().then(function () {
              var dbInfo = self._dbInfo;
              dbInfo.db.transaction(function (t) {
                  tryExecuteSql(t, dbInfo, 'DELETE FROM ' + dbInfo.storeName, [], function () {
                      resolve();
                  }, function (t, error) {
                      reject(error);
                  });
              });
          })["catch"](reject);
      });
  
      executeCallback(promise, callback);
      return promise;
  }
docs: Deletes every item in the table. TODO: Find out if this resets the AUTO_INCREMENT number.