Yes, but for tests like [this](https://github.com/edx/edx-platform/blob/master/lms/djangoapps/courseware/features/video.feature#L158) where asset is added, but fields `sub` and `transcripts` are empty, we'll use `self.course_fix.add_asset(self.transcript)` in my test anyway. So, I want to see 1 explicit way to work with assets. What do you think?