[erlang-questions] Optional callbacks

[Loïc Hoguin]

Started trying to play with those, and not managing to get a warning 
from Dialyzer.

When I change the body of the function to 'ok', I do get a warning for a 
normal callback, and I get nothing for an optional callback.

Is that normal?

The behaviour_info function does return the callback as optional.

-- 
Loïc Hoguin
http://ninenines.eu
Author of The Erlanger Playbook,
A book about software development using Erlang