      pass
  
  
  class Recommendation(Title):
      recommender = models.ForeignKey(Recommender)
  
  
  class Collector(models.Model):
      name = models.CharField(max_length=100)
  
 
</s> remove     title = models.ForeignKey(Title)
 </s> add     title = models.ForeignKey(Title, models.CASCADE) </s> remove     album1 = models.ForeignKey(Album, related_name="album1_set")
    album2 = models.ForeignKey(Album, related_name="album2_set")
 </s> add     album1 = models.ForeignKey(Album, models.CASCADE, related_name="album1_set")
    album2 = models.ForeignKey(Album, models.CASCADE, related_name="album2_set") </s> remove     restaurant = models.ForeignKey(Restaurant)
 </s> add     restaurant = models.ForeignKey(Restaurant, models.CASCADE) </s> remove     collection = models.ForeignKey(ProfileCollection, blank=True, null=True)
 </s> add     collection = models.ForeignKey(ProfileCollection, models.SET_NULL, blank=True, null=True) </s> remove     a1 = models.ForeignKey('lookuperror_a.A1')
 </s> add     a1 = models.ForeignKey('lookuperror_a.A1', models.CASCADE)
    recommender = models.ForeignKey(Recommender, models.CASCADE)
      pass
  
  
  class Recommendation(Title):
    recommender = models.ForeignKey(Recommender, models.CASCADE)
  
  
  class Collector(models.Model):
      name = models.CharField(max_length=100)
  
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