      def __str__(self):
          return self.title
  
  
  @python_2_unicode_compatible
  class ModelWithNullFKToSite(models.Model):
      title = models.CharField(max_length=200)
      site = models.ForeignKey(Site, null=True, on_delete=models.CASCADE)
      post = models.ForeignKey(Post, null=True, on_delete=models.CASCADE)
  
 
</s> remove @python_2_unicode_compatible
 </s> add  </s> remove @python_2_unicode_compatible
 </s> add  </s> remove @python_2_unicode_compatible
 </s> add  </s> remove @python_2_unicode_compatible
 </s> add  </s> remove @python_2_unicode_compatible
 </s> add 
      def __str__(self):
          return self.title
  
  

  class ModelWithNullFKToSite(models.Model):
      title = models.CharField(max_length=200)
      site = models.ForeignKey(Site, null=True, on_delete=models.CASCADE)
      post = models.ForeignKey(Post, null=True, on_delete=models.CASCADE)
  
keep keep keep keep replace keep keep keep keep keep
 Refs #23919 -- Removed python_2_unicode_compatible decorator usage 
tests/contenttypes_tests/models.py