+ relation = create(:relation)
+ node = create(:node)
+ way = create(:way)
+ other_relation = create(:relation)
+ create(:relation_member, :relation => relation, :member => node, :member_role => "some node")
+ create(:relation_member, :relation => relation, :member => way, :member_role => "some way")
+ create(:relation_member, :relation => relation, :member => other_relation, :member_role => "some relation")
+