pg-promise Chaining Queries for Task and Transactions

I have seen pg-promise tasks and tx to reuse same connection we can use

db.task(t => {
return t.one('SELECT id FROM Users WHERE name = $1', 'John')
    .then(user => {
        return t.any('SELECT * from Events WHERE userId = $1', user.id);
    });}).then(events => {// success
 }).catch(error => {
// error
});

But what if I have two different files and e.g. UsersModel.getUser(username) and EvenModel.getUserEvent(userId). Is there any way I can pass transaction or task objects.

thanks

via dev123