title: how to add annotate data in django-rest-framework queryset responses?
body: <p>I am generating aggregates for each item in a QuerySet:</p>
  
  <pre><code>def get_queryset(self):
      from django.db.models import Count
      queryset = Book.objects.annotate(Count('authors'))
      return queryset
  </code></pre>
  
  <p>But I am not getting the count in the JSON response.</p>
  
  <p>thank you in advance.</p>