new_contents: from django.test import TestCase
  
  from holonet.core.fields import DomainField, LocalPartField
  
  
  class DomainFieldTestCase(TestCase):
  
      def setUp(self):
          self.field = DomainField()
  
      def test_clean(self):
          self.assertEqual(self.field.clean('VG.no', None), 'vg.no')
  
      def test_formfield(self):
          field = self.field.formfield()
          self.assertTrue('invalid' in field.error_messages.keys())
  
  
  class LocalPartFieldTestCase(TestCase):
  
      def setUp(self):
          self.field = LocalPartField()
  
      def test_clean(self):
          self.assertEqual(self.field.clean('HolOnet', None), 'holonet')
  
      def test_formfield(self):
          field = self.field.formfield()
          self.assertTrue('invalid' in field.error_messages.keys())
  
subject: Add field tests