[gentoo-dev] About *ECLASS_ONCE_* stuff at top of some eclasses but not others

[Pacho Ramos]

What is the purpose of this stuff:
if [[ ${___ECLASS_ONCE_EUTILS} != "recur -_+^+_- spank" ]] ; then
___ECLASS_ONCE_EUTILS="recur -_+^+_- spank"

and similar in some eclasses (like eutils, multilib) but not others
(like python-single-r1 that I was looking some days ago for learning how
to use it)?

Thanks a lot for the info