old_contents: # -*- coding: utf-8 -*-
  from __future__ import unicode_literals
  
  from django.db import models, migrations
  
  
  class Migration(migrations.Migration):
      dependencies = [
          ('cms', '0001_initial'),
      ]
  
      operations = [
          migrations.CreateModel(
              name='IframePlugin',
              fields=[
                  ('cmsplugin_ptr', models.OneToOneField(parent_link=True, auto_created=True, primary_key=True, serialize=False, to='cms.CMSPlugin')),
                  ('src', models.URLField()),
              ],
              options={
                  'abstract': False,
              },
              bases=('cms.cmsplugin',),
          ),
      ]
  
new_contents: # -*- coding: utf-8 -*-
  from __future__ import unicode_literals
  
  from django.db import models, migrations
  
  
  class Migration(migrations.Migration):
      dependencies = [
          ('cms', '0001_initial'),
      ]
  
      operations = [
          migrations.CreateModel(
              name='IframePlugin',
              fields=[
                  ('cmsplugin_ptr', models.OneToOneField(parent_link=True, auto_created=True, primary_key=True, serialize=False, to='cms.CMSPlugin', on_delete=models.CASCADE)),
                  ('src', models.URLField()),
              ],
              options={
                  'abstract': False,
              },
              bases=('cms.cmsplugin',),
          ),
      ]
  
subject: Add in on_delete clause to work with more modern versions of Django