code: def response_add(self, request, obj, post_url_continue=POST_URL_CONTINUE):
          
          if '_addanother' not in request.POST and '_popup' not in request.POST:
              request.POST['_continue'] = 1
          return super(ExportAdmin, self).response_add(request,
                                                       obj,
                                                       post_url_continue)
docs: If we're adding, save must be "save and continue editing"
  
          Two exceptions to that workflow:
          * The user has pressed the 'Save and add another' button
          * We are adding a user in a popup