lfottaviano/emesene — comment on commit 0714d21ead934eb2b3e188783dbf50c0f54503ca
File: emesene/gui/gtkui/Conversation.py line 320
By lfottaviano:

Yes I understood you, but I thought that is better comparing to None, because If None, will use is_sensitive parameter for block button too.
If you set it as default to False or True, you can't to this,.