title: ContentNotRenderedError : The response content must be rendered before it can be iterated over
body: <p>while returning custom response I having render error.
  I am using django 1.8 and DRF 2.4.8</p>
  
  <p>view is</p>
  
  <pre><code>class UserList(generics.ListAPIView):
  # queryset = User.objects.all()
  serializer_class = UserSerializer
  
  def get_queryset(self):
      is_staff = self.request.GET.get('is_staff', None)
      is_superuser = self.request.GET.get('is_superuser', None)
      is_admin = self.request.GET.get('is_admin', None)
      company = self.request.GET.get('company', None)
      userdetails = UserData(self.request.user).userdetails()
      print(userdetails.get('usertype'))
      query1 = query = Q()
      if is_staff:
          query1.add(Q(is_staff=is_staff), Q.AND)
      if is_superuser:
          query1.add(Q(is_superuser=is_superuser), Q.AND)
      if is_admin:
          query = Q(is_admin=is_admin)
      if company:
          query.add(Q(company__name=company), Q.AND)
      if userdetails.get('usertype') is 'superuser':
          if is_admin or company:
              profile_list = Profile.objects.filter(query).values_list('user_id', flat=True)
              user_list = User.objects.filter(id__in=profile_list)
              return user_list.filter(query1)
          else:
              return User.objects.filter(query1)
      elif userdetails.get('usertype') in ['staff', 'admin']:
          up = Profile.objects.get(user=self.request.user)
          profile_list = Profile.objects.filter(company=up.company)  # .values_list('user_id', flat=True)
          user_list = profile_list.filter(query).values_list('user_id', flat=True) if is_admin or company else \
              profile_list.values_list('user_id', flat=True)
          final_list = User.objects.filter(id__in=user_list)
          return final_list.filter(query1)
      else:
          return Response(data={"error": ["You don't have enough permission."]}, status=status.HTTP_400_BAD_REQUEST)
  </code></pre>
  
  <p>while returning response from last else part I am getting error?
  What is the solution? what is wrong in <code>Response()</code>?</p>