title: Django serialize to JSON
body: <p>I have a Django model (schedule) with the class of entity, that is the parent of <code>Activity</code>, that is the parent of <code>Event</code>.</p>
  
  <pre><code>class Entity(models.Model):
      &lt;...&gt;
  
  class Activity(models.Model):
      &lt;...&gt;
      team_entity = models.ForeignKey(Entity)
      &lt;...&gt;   
  
  class Event(models.Model):
      &lt;...&gt;
      activity = models.ForeignKey(Activity)
      &lt;...&gt;
  </code></pre>
  
  <p>How do I serialize and get both the child object and grand children as part of the JSON file?</p>