title: factory-boy create a list of SubFactory for a Factory
body: <p>I am using django 1.6 and factory-boy. </p>
  
  <pre><code>class UserFactory(factory.Factory):
     class Meta:
        model = models.User
  
     username = factory.Sequence(lambda n: 'user%d' % n)
  </code></pre>
  
  <p>Here <code>username</code> is a simple <code>CharField</code> in model. So that each time I am calling <code>UserFactory()</code> I am saving and getting unique user named object.</p>
  
  <p>In factory-boy I can use <code>factory.SubFactory(SomeFactory)</code>.</p>
  
  <p>How I can generate list of <code>SomeFactory</code> in <code>ParentOfSomeFactory</code> ?</p>
  
  <p>So that, if I call <code>ParentOfSomeFactory()</code> I will create list of SomeFactory as well as ParentOfSomeFactory database </p>