title: How to properly use factories having multiple associations to the same model?
body: <p>I am using Ruby on Rails 3.2.2, FactoryGirl 3.1.0 and FactoryGirlRails 3.1.0. I have a model that has two association to another model:</p>
  
  <pre><code>class Article &lt; ActiveRecord::Base
    belongs_to a_users, :class_name  =&gt; 'User'
    belongs_to b_users, :class_name  =&gt; 'User'
  end
  </code></pre>
  
  <p>In my factory file I have:</p>
  
  <pre><code>factory :article, :class =&gt; Article do
    title "Sample title"
  
    association :a_users, factory: :user
    association :b_users, factory: :user
  end
  </code></pre>
  
  <p>By using the above code it will create <em>two</em> users, but <em>I would like that both associations have the same user</em> (without to create multiple users). How can I make that?</p>