src/batoh.js
function(storeName, transaction, cb) {
    try {
      return transaction.objectStore(storeName);
    } catch (err) {
      if (isFunction(cb)) return cb(err);
    }
  }
function(storeName, transaction, cb) {
    try {
      return transaction.objectStore(storeName);
    } catch (err) {
      if (isFunction(cb)) return cb(err);
    }
  }
function ( storeName , transaction , cb ) { try { return transaction . objectStore ( storeName ) ; } catch ( err ) { if ( isFunction ( cb ) ) return cb ( err ) ; } }
Wrap IDBTransation.objectStore

@param {String} storeName - name of the object store to use.
@param {IDBTransaction} transaction - to use.
@param {Function} callback - gets one argument `(err)`,
if there is no error, it won't be called.
Wrap IDBTransation . objectStore