docs: def destroy(self, request, *args, **kwargs):
          """Destroy a model instance.
  
          If ``delete_content`` flag is set in query parameters, also all
          Data objects contained in entity will be deleted.
          """
          obj = self.get_object()
          user = request.user
  
          if strtobool(request.query_params.get('delete_content', 'false')):
              for data in obj.data.all():
                  if user.has_perm('edit_data', data):
                      data.delete()
  
              # If all data objects in an entity are removed, the entity may
              # have already been removed, so there is no need to call destroy.
              if not Entity.objects.filter(pk=obj.pk).exists():
                  return Response(status=status.HTTP_204_NO_CONTENT)
  
          # NOTE: Collection's ``destroy`` method should be skiped, so we
          # intentionaly call it's parent.
          return super(CollectionViewSet, self).destroy(  # pylint: disable=no-member,bad-super-call
              request, *args, **kwargs
          )