code: def get_queryset(self):
          
          qs = super(PrefetchForIncludesHelperMixin, self).get_queryset()
          if not hasattr(self, 'prefetch_for_includes'):
              return qs
  
          includes = self.request.GET.get('include', '').split(',')
          for inc in includes + ['__all__']:
              prefetches = self.prefetch_for_includes.get(inc)
              if prefetches:
                  qs = qs.prefetch_related(*prefetches)
  
          return qs
docs: This viewset provides a helper attribute to prefetch related models
          based on the include specified in the URL.
  
          __all__ can be used to specify a prefetch which should be done regardless of the include
  
          .. code:: python
  
              # When MyViewSet is called with ?include=author it will prefetch author and authorbio
              class MyViewSet(viewsets.ModelViewSet):
                  queryset = Book.objects.all()
                  prefetch_for_includes = {
                      '__all__': [],
                      'author': ['author', 'author__authorbio'],
                      'category.section': ['category']
                  }