old_contents: from django.contrib.gis.db import models
  from django.utils.translation import ugettext_lazy as _
  
  from countries.fields import InternalCountryFileField
  
  
  class Country(models.Model):
      name = models.CharField(verbose_name=_('name'), max_length=100)
      polyfile = InternalCountryFileField(verbose_name=_('polyfile'))
      simplified_polygon = models.MultiPolygonField(verbose_name=_('simplified area'))
  
new_contents: from django.contrib.gis.db import models
  from django.utils.translation import ugettext_lazy as _
  
  from countries.fields import InternalCountryFileField
  
  
  class Country(models.Model):
      name = models.CharField(verbose_name=_('name'), max_length=100)
      polyfile = InternalCountryFileField(verbose_name=_('polyfile'))
      simplified_polygon = models.MultiPolygonField(verbose_name=_('simplified area'))
  
      def __str__(self):
          return self.name
  
subject: use name as string representation for country