  @python_2_unicode_compatible
  class FunkyTag(models.Model):
      "Because we all know there's only one real use case for GFKs."
      name = models.CharField(max_length=25)
      content_type = models.ForeignKey(ContentType)
      object_id = models.PositiveIntegerField()
      content_object = GenericForeignKey('content_type', 'object_id')
  
      def __str__(self):
          return self.name
 
</s> remove     content_type = models.ForeignKey(ContentType)
 </s> add     content_type = models.ForeignKey(ContentType, models.CASCADE) </s> remove     content_type = models.ForeignKey(ContentType)
 </s> add     content_type = models.ForeignKey(ContentType, models.CASCADE) </s> remove     content_type = models.ForeignKey(ContentType)
 </s> add     content_type = models.ForeignKey(ContentType, models.CASCADE) </s> remove     content_type = models.ForeignKey(ContentType, related_name='tagged_items')
 </s> add     content_type = models.ForeignKey(ContentType, models.CASCADE, related_name='tagged_items') </s> remove     one = models.ForeignKey(CyclicOne)
 </s> add     one = models.ForeignKey(CyclicOne, models.CASCADE)
    content_type = models.ForeignKey(ContentType, models.CASCADE)
  @python_2_unicode_compatible
  class FunkyTag(models.Model):
      "Because we all know there's only one real use case for GFKs."
      name = models.CharField(max_length=25)
    content_type = models.ForeignKey(ContentType, models.CASCADE)
      object_id = models.PositiveIntegerField()
      content_object = GenericForeignKey('content_type', 'object_id')
  
      def __str__(self):
          return self.name
keep keep keep keep replace keep keep keep keep keep
 Fixed #21127 -- Started deprecation toward requiring on_delete for ForeignKey/OneToOneField 
tests/admin_views/models.py