Comparison trait should be able to be created from an attr fun
Example:
:COMPARE.require_from('kink/') :Xxx_trait <- [ ... COMPARE.trait{(C) C.by{(:X) X.num } } ]
Working on the branch issue_0039933-comapre-by
Closed by the commit d43e8ac0e7e6236450b74c825ca8844b8c176814
Example: