If I remember correctly, `deferred` requires that you pass an Error instance to its `resolve()` method, and it looks like the adapter was changed in this pull request to pass the value through.  So, changing this line to pass undefined will pass it directly through to `deferred`'s resolve, which will fulfill, instead of rejecting.

IMHO, `deferred`'s adapter *should* internally create the Error instance *because this is a necessary penalty* in `deferred`'s case.  Other libs do not force you to create an Error instance.