code: def get_urls(self):
          
          urls = super(SimpleHistoryAdmin, self).get_urls()
          admin_site = self.admin_site
          opts = self.model._meta
          info = opts.app_label, opts.model_name
          history_urls = [
              url(
                  "^([^/]+)/history/([^/]+)/$",
                  admin_site.admin_view(self.history_form_view),
                  name="%s_%s_simple_history" % info,
              )
          ]
          return history_urls + urls
docs: Returns the additional urls used by the Reversion admin.