ruby-on-rails-3 - A FactoryGirl factory for a many-to-many self-referenced model

Question

I've got a self-referenced user model:

class User < ActiveRecord::Base
    has_and_belongs_to_many :following,
                            :class_name               => "User",
                            :foreign_key              => 'follower_id',
                            :association_foreign_key  => 'following_id',
                            :join_table               => 'followers'
    has_and_belongs_to_many :followers,
                            :class_name               => "User",
                            :foreign_key              => 'following_id',
                            :association_foreign_key  => 'follower_id',
                            :join_table               => 'followers'
    ...
end

I'm having trouble coming up with a FactoryGirl factory to test this behavior. I've tried some variations of

factory :user do
    ...
    factory :following do
        after(:create) do |user, evaluator|
            create_list(:user, evaluator.followers_count, follower: user)
        end
    end
end

but had no luck with it. How would you do this? Thanks for any input.