How to use transactions in koajs + sequelize?

Question

Node.js

How to wrap it in a transaction?

app.use(_.post('/books', function *() {
  var book = yield Book.create({});
  yield book.addOwner(this.user);
}));

Answer 1

Everything is in the documentation https://sequelize.org/master/manual/transactions.html
var, yield, function *()
what year is it? 2017?