  
      def test_fk_instantiation_outside_model(self):
          # Regression for #12190 -- Should be able to instantiate a FK outside
          # of a model, and interrogate its related field.
          cat = models.ForeignKey(Category)
          self.assertEqual('id', cat.remote_field.get_related_field().name)
  
      def test_relation_unsaved(self):
          # Test that the <field>_set manager does not join on Null value fields (#17541)
          Third.objects.create(name='Third 1')
 
</s> remove     user = models.OneToOneField(User, primary_key=True)
 </s> add     user = models.OneToOneField(User, models.CASCADE, primary_key=True) </s> remove     parent = models.ForeignKey(ParentWithDependentChildren)
 </s> add     parent = models.ForeignKey(ParentWithDependentChildren, models.CASCADE) </s> remove     honeycomb = models.ForeignKey(Honeycomb)
 </s> add     honeycomb = models.ForeignKey(Honeycomb, models.CASCADE) </s> remove         company_that_makes_it = models.ForeignKey(Manufacturer)
 </s> add         company_that_makes_it = models.ForeignKey(
            Manufacturer,
            on_delete=models.CASCADE,
        ) </s> remove     parent = models.OneToOneField(Place)
 </s> add     parent = models.OneToOneField(Place, models.CASCADE)
        cat = models.ForeignKey(Category, models.CASCADE)
  
      def test_fk_instantiation_outside_model(self):
          # Regression for #12190 -- Should be able to instantiate a FK outside
          # of a model, and interrogate its related field.
        cat = models.ForeignKey(Category, models.CASCADE)
          self.assertEqual('id', cat.remote_field.get_related_field().name)
  
      def test_relation_unsaved(self):
          # Test that the <field>_set manager does not join on Null value fields (#17541)
          Third.objects.create(name='Third 1')
keep keep keep keep replace keep keep keep keep keep
 Fixed #21127 -- Started deprecation toward requiring on_delete for ForeignKey/OneToOneField 
tests/many_to_one/tests.py