old_contents: from django.contrib.gis.db import models
  from django.core.urlresolvers import reverse
  from boundaries.models import Boundary
  from opencivicdata.models import Division
  
  
  class DivisionGeometry(models.Model):
      division = models.ForeignKey(Division, related_name='geometries')
      boundary = models.ForeignKey(Boundary, related_name='geometries')
  
      def __unicode__(self):
          return '{0} - {1} - {2}'.format(self.division, self.temporal_set, self.boundary)
  
new_contents: from django.contrib.gis.db import models
  from django.core.urlresolvers import reverse
  from boundaries.models import Boundary
  from opencivicdata.models import Division
  
  
  class DivisionGeometry(models.Model):
      division = models.ForeignKey(Division, related_name='geometries')
      boundary = models.ForeignKey(Boundary, related_name='geometries')
  
      def __unicode__(self):
          return '{0} - {1} - {2}'.format(self.division, self.boundary)
  
subject: remove old temporal set reference