text: from django.core.urlresolvers import reverse
  from django.contrib.auth.models import  User
  from django.utils.translation import ugettext_lazy as _
  from django.db import models
  
  from groups_ng.base import Group
  
  class Tribe(Group):
      members = models.ManyToManyField(User, related_name='tribes',
          verbose_name=_('members'))
  
      def get_absolute_url(self):
          return reverse('tribe_detail', kwargs={'group_slug': self.slug})
      
      def get_url_kwargs(self):
          return {'group_slug': self.slug}