old_contents: #!/usr/bin/env python
  # -*- coding: utf-8 -*-
  from opps.core.models import Publishable
  
  
  class SitePermission(Publishable):
      """
      Join user in site
      """
      pass
  
new_contents: #!/usr/bin/env python
  # -*- coding: utf-8 -*-
  from opps.core.models import Publishable
  from django.utils.translation import ugettext_lazy as _
  
  
  class SitePermission(Publishable):
      """
      Join user in site
      """
      class Meta:
          verbose_name = _(u'Site Permission')
          verbose_name_plural = _(u'Site Permissions')
  
subject: Add missing meta class in multisite models