vendor/rails/activerecord/test/fixtures/memberships.yml

   1 membership_of_boring_club:
   2   joined_on: <%= 3.weeks.ago.to_s(:db) %>
   3   club: boring_club
   4   member: groucho
   5   favourite: false
   6   type: CurrentMembership
   7
   8 membership_of_favourite_club:
   9   joined_on: <%= 3.weeks.ago.to_s(:db) %>
  10   club: moustache_club
  11   member: groucho
  12   favourite: true
  13   type: Membership
  14
  15 other_guys_membership:
  16   joined_on: <%= 4.weeks.ago.to_s(:db) %>
  17   club: boring_club
  18   member: some_other_guy
  19   favourite: false
  20   type: CurrentMembership