Making sure that Job.update completes

I have as serious problem regarding the `job.update` method.
I need to be able to ensure that it has completed.

So would it be possible to make it blocking or attach a callback to it that fire
when update has been performed?

Start by locating the job.update entry point in the Kue repository and read how its asynchronous operation reports completion. Determine whether the requested behavior is a blocking update or a completion callback, then verify the chosen behavior with the existing job-update tests, if present; done means callers can reliably know when the update has finished.

Written by the indexing model from the issue text.