old_contents: from django.test import TestCase
  
  from conman.nav_tree.tests.test_models import NODE_BASE_FIELDS
  from .. import models
  
  
  class PageTest(TestCase):
      def test_fields(self):
          expected = (
              'id',
              'node_ptr',
              'node_ptr_id',
              'content',
          ) + NODE_BASE_FIELDS
          fields = models.Page._meta.get_all_field_names()
          self.assertCountEqual(fields, expected)
  
new_contents: from django.test import TestCase
  
  from conman.nav_tree.tests.test_models import NODE_BASE_FIELDS
  from .. import models
  
  
  class PageTest(TestCase):
      def test_fields(self):
          """Check Page has Node's fields and a few of its own."""
          expected = (
              'id',
              'node_ptr',
              'node_ptr_id',
              'content',
          ) + NODE_BASE_FIELDS
          fields = models.Page._meta.get_all_field_names()
          self.assertCountEqual(fields, expected)
  
subject: Add docstring to pages.tests.test_models