  
  
  class Flea(models.Model):
      id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
      current_room = models.ForeignKey(Room, related_name='fleas', null=True)
      pets_visited = models.ManyToManyField(Pet, related_name='fleas_hosted')
      people_visited = models.ManyToManyField(Person, related_name='fleas_hosted')
 
</s> remove     parent = models.ForeignKey(AutoPKParent)
 </s> add     parent = models.ForeignKey(AutoPKParent, models.CASCADE) </s> remove     parent = models.ForeignKey(UUIDPKParent)
 </s> add     parent = models.ForeignKey(UUIDPKParent, models.CASCADE) </s> remove     custom = models.ForeignKey(CustomPk)
 </s> add     custom = models.ForeignKey(CustomPk, models.CASCADE) </s> remove     parent = models.ForeignKey(Parent, editable=False)
 </s> add     parent = models.ForeignKey(Parent, models.CASCADE, editable=False) </s> remove         parent = models.ForeignKey(RangesModel, blank=True, null=True)
 </s> add         parent = models.ForeignKey(RangesModel, models.SET_NULL, blank=True, null=True)
    current_room = models.ForeignKey(Room, models.SET_NULL, related_name='fleas', null=True)
  
  
  class Flea(models.Model):
      id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
    current_room = models.ForeignKey(Room, models.SET_NULL, related_name='fleas', null=True)
      pets_visited = models.ManyToManyField(Pet, related_name='fleas_hosted')
      people_visited = models.ManyToManyField(Person, related_name='fleas_hosted')
keep keep keep keep replace keep keep
 Fixed #21127 -- Started deprecation toward requiring on_delete for ForeignKey/OneToOneField 
tests/prefetch_related/models.py