Hi Chris, Thanks for your patch.
However, a better patch would be to use the sample_default= directive of oslo.config, which is printing in the generated doc, whatever the value of sample_default, while continuing to keep the default= value that can contain something programmatic. This avoids writing the "if blah is None" as you've put it.
I've sent this upstream and patched olso.messaging accordingly. Cheers, Thomas Goirand (zigo)
