sequence of hash with factory_girl

factories.rb

  Factory.sequence :writer_hash do |n| 
      {
        "id" => "#{n}", 
        "name" => "name#{n}", 
        "article" => {
          "id" => "#{n}",
          "title" => "post title #{n}"
        }
      }
  end

  factory :publisher do |p|
    l.association :owner, :factory => :user
    l.raw_writers [Factory.next :writer_hash, Factory.next :writer_hash, Factory.next :writer_hash ]
  end