Get a collections parent model

Is there away get a collections parent model from within the
collection itself? Where the collection looks like this:

User.first.events.upcoming
or
Group.first.events.upcoming.

If the upcoming method is in a mix-in that is shared by two different
models how could you find what the parent model is (Group or User)?

Found it:

proxy_owner

User.first.events.upcoming

def upcoming
case self.proxy_owner.class
when User

do stuff for User

when Group

do stuff for groups

else
end
end