  @python_2_unicode_compatible
  class Restaurant(Place, Rating):
      serves_hot_dogs = models.BooleanField(default=False)
      serves_pizza = models.BooleanField(default=False)
      chef = models.ForeignKey(Chef, null=True, blank=True)
  
      class Meta(Rating.Meta):
          db_table = 'my_restaurant'
  
      def __str__(self):
 
</s> remove     related = models.ForeignKey(RelatedModel)
 </s> add     related = models.ForeignKey(RelatedModel, models.CASCADE) </s> remove     related = models.OneToOneField(RelatedModel)
 </s> add     related = models.OneToOneField(RelatedModel, models.CASCADE) </s> remove     leader = models.ForeignKey(Actor)
 </s> add     leader = models.ForeignKey(Actor, models.CASCADE) </s> remove     silly_tribble = models.ForeignKey("migrations.Tribble")
 </s> add     silly_tribble = models.ForeignKey("migrations.Tribble", models.CASCADE) </s> remove     post = models.ForeignKey("Post")
 </s> add     post = models.ForeignKey("Post", models.CASCADE)
    chef = models.ForeignKey(Chef, models.SET_NULL, null=True, blank=True)
  @python_2_unicode_compatible
  class Restaurant(Place, Rating):
      serves_hot_dogs = models.BooleanField(default=False)
      serves_pizza = models.BooleanField(default=False)
    chef = models.ForeignKey(Chef, models.SET_NULL, null=True, blank=True)
  
      class Meta(Rating.Meta):
          db_table = 'my_restaurant'
  
      def __str__(self):
keep keep keep keep replace keep keep keep keep keep
 Fixed #21127 -- Started deprecation toward requiring on_delete for ForeignKey/OneToOneField 
tests/model_inheritance/models.py