What are you doing?

I want to globally use REPEATABLE_READ as transaction isolation level unless overridden. This was the behaviour for in sequelize 3 and I missed that this was mentioned in the migration docs, (it is, i saw it today).

In one part of the docs
http://docs.sequelizejs.com/manual/tutorial/transactions.html#isolation-levels
I find the following

By default, sequelize uses the isolation level of the database. If you want to use a different isolation level, pass in the desired level as the first argument:

And in another part
http://docs.sequelizejs.com/class/lib/transaction.js~Transaction.html
I find the following

Isolations levels can be set per-transaction by passing options.isolationLevel to sequelize.transaction. Default to REPEATABLE_READ but you can override the default isolation level by passing options.isolationLevel in new Sequelize.

What do you expect to happen?

I would like the second part to be update to match the system, and I would also like to have a way to globally override the default isolation level, to easily get back to the v3 behavior. Manually adding an override on every transaction seems like a pain.