Improved handling of errors in notebook_extension #1290
Looks good but could you mention exactly what the old behavior was and how the new behavior improve it?
In addition, I assume this doesn't fix the issue with the output magic where switching to matplotlib (when only bokeh has been loaded) doesn't issue an appropriate warning. Or does it? If not, it is something I wouldn't mind being included in this PR.
Yes, sorry lost my comment somewhere. Basically this does two things that probably mostly affect developers.