title: How to use factory.LazyAttribute with Faker() functions
body: <p>I am using <code>factory_boy</code> to build some fixtures in Django.</p>
  <p>I want to use <a href="https://factoryboy.readthedocs.io/en/latest/reference.html?highlight=lazy#factory.LazyAttribute" rel="nofollow noreferrer"><code>factory.LazyAttribute</code></a> to build one attribute based on the condition of another attribute.</p>
  <pre><code>class MyFactory(factory.django.DjangoModelFactory):
      class Meta:
          model = MyModel
  
      title = 'My Title' if random() &lt; 0.5 else None
      description = factory.LazyAttribute(
          lambda a: factory.Faker(
              'paragraph', nb_sentences=1, variable_nb_sentences=False
          ) if a.title else None)
  </code></pre>
  <p>However, this returns a <code>string</code> being <code>&lt;factory.faker.Faker object at 0x000001B10597BB20&gt;</code> rather than executing the correct paragraph generation.</p>
  <p>Where am I going wrong?</p>