code: def logout(request, login_url=None, **kwargs):
      
      msg = 'Logging out user "%(username)s".' % \
          {'username': request.user.username}
      LOG.info(msg)
  
      """ Securely logs a user out. """
      if (utils.is_websso_enabled and utils.is_websso_default_redirect() and
              utils.get_websso_default_redirect_logout()):
          auth_user.unset_session_user_variables(request)
          return django_http.HttpResponseRedirect(
              utils.get_websso_default_redirect_logout())
      else:
          return django_auth_views.logout_then_login(request,
                                                     login_url=login_url,
                                                     **kwargs)
docs: Logs out the user if he is logged in. Then redirects to the log-in page.
  
      :param login_url:
          Once logged out, defines the URL where to redirect after login
  
      :param kwargs:
          see django.contrib.auth.views.logout_then_login extra parameters.