old_contents: """
  Model fields for the countries app.
  """
  
  from django.db import models
  from django.utils import six
  from django.utils.translation import ugettext_lazy as _
  
  from .countries import COUNTRIES_CHOICES
  
  
  class CountryFieldBase(models.CharField):
      """
      This database model field can be used to store the name of a country.
      """
  
      description = _('A country name object')
  
      MAX_LENGTH = 3
  
      def __init__(self, *args, **kwargs):
          parent_kwargs = {
              'max_length': self.MAX_LENGTH,
              'choices': COUNTRIES_CHOICES,
              }
          parent_kwargs.update(kwargs)
          super(CountryFieldBase, self).__init__(*args, **parent_kwargs)
  
      def deconstruct(self):
          name, path, args, kwargs = super(CountryFieldBase, self).deconstruct()
          if kwargs['choices'] == COUNTRIES_CHOICES:
              del kwargs['choices']
          if kwargs['max_length'] == self.MAX_LENGTH:
              del kwargs['max_length']
          return name, path, args, kwargs
  
      def get_internal_type(self):
          return "CharField"
  
  
  class CountryField(six.with_metaclass(models.SubfieldBase,
                                        CountryFieldBase)):
      """
      Database Country field. Can be used to store a country name.
      See ``CountryFieldBase`` for details.
      """
      pass
new_contents: """
  Model fields for the countries app.
  """
  
  from django.db import models
  from django.utils import six
  from django.utils.translation import ugettext_lazy as _
  
  from .countries import COUNTRIES_CHOICES
  
  
  class CountryFieldBase(models.CharField):
      """
      This database model field can be used to store the name of a country.
      """
  
      description = _('A country name object')
  
      MAX_LENGTH = 3
  
      def __init__(self, *args, **kwargs):
          parent_kwargs = {
              'max_length': self.MAX_LENGTH,
              'choices': COUNTRIES_CHOICES,
              }
          parent_kwargs.update(kwargs)
          super(CountryFieldBase, self).__init__(*args, **parent_kwargs)
  
      def deconstruct(self):
          name, path, args, kwargs = super(CountryFieldBase, self).deconstruct()
          if kwargs['choices'] == COUNTRIES_CHOICES:
              del kwargs['choices']
          if kwargs['max_length'] == self.MAX_LENGTH:
              del kwargs['max_length']
          return name, path, args, kwargs
  
      def get_internal_type(self):
          return "CharField"
  
  
  class CountryField(six.with_metaclass(models.SubfieldBase,
                                        CountryFieldBase)):
      """
      Database Country field. Can be used to store a country name.
      See ``CountryFieldBase`` for details.
      """
      pass
  
subject: Add missing eof line