      pass
  
  
  class Title(models.Model):
      collection = models.ForeignKey(TitleCollection, blank=True, null=True)
      title1 = models.CharField(max_length=100)
      title2 = models.CharField(max_length=100)
  
  # Models for #15424
  
 
</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     et = models.ForeignKey(ExtraTerrestrial)
 </s> add     et = models.ForeignKey(ExtraTerrestrial, models.CASCADE) </s> remove     parent = models.ForeignKey('self', null=True, blank=True)
 </s> add     parent = models.ForeignKey('self', models.SET_NULL, null=True, blank=True) </s> remove     alfa = models.ForeignKey(Alfa, null=True)
    bravo = models.ForeignKey(Bravo, null=True)
 </s> add     alfa = models.ForeignKey(Alfa, models.SET_NULL, null=True)
    bravo = models.ForeignKey(Bravo, models.SET_NULL, null=True) </s> remove     site = models.ForeignKey(Site, related_name="admin_articles")
 </s> add     site = models.ForeignKey(Site, models.CASCADE, related_name="admin_articles")
    collection = models.ForeignKey(TitleCollection, models.SET_NULL, blank=True, null=True)
      pass
  
  
  class Title(models.Model):
    collection = models.ForeignKey(TitleCollection, models.SET_NULL, blank=True, null=True)
      title1 = models.CharField(max_length=100)
      title2 = models.CharField(max_length=100)
  
  # Models for #15424
  
keep keep keep keep replace keep keep keep keep keep
 Fixed #21127 -- Started deprecation toward requiring on_delete for ForeignKey/OneToOneField 
tests/admin_inlines/models.py