[Mne_analysis] on_missing and time-frequency

[Alexandre Gramfort]

> The reason is purely pragmatic for batch processing (all runs of all
> participants; in some runs there may be some conditions missing due to the
> nature of the task)

either we have it crash at epochs creation or it will crash later.

I think you should detect it and address the problem
on your side when running your batch script.

ALex