There are three logical data streams:
- CDC to coprocessor
- CDC to ESP tunnel
- ESP to coprocessor
![obrazek](https://user-images.githubusercontent.com/3955056/79015576-51aa7a00-7b6d-11ea-896…
In the process of creating the boundary-element model meshes, I run into the following error when executing `mne.bem.make_watershed_bem('fsaverage', overwrite=True)` with the development version of Fr…