      name = models.CharField(max_length=100)
  
  
  class Child(models.Model):
      mother = models.ForeignKey(Parent, related_name='mothers_children')
      father = models.ForeignKey(Parent, related_name='fathers_children')
      school = models.ForeignKey(School)
      name = models.CharField(max_length=100)
  
  
  @python_2_unicode_compatible
  class Poet(models.Model):
 
</s> remove     parent = models.ForeignKey(Parent, editable=False, null=True)
 </s> add     parent = models.ForeignKey(Parent, models.SET_NULL, editable=False, null=True) </s> remove     parent = models.ForeignKey(Parent, editable=False)
 </s> add     parent = models.ForeignKey(Parent, models.CASCADE, editable=False) </s> remove             parent = models.ForeignKey(Parent)
 </s> add             parent = models.ForeignKey(Parent, models.CASCADE) </s> remove     owner = models.ForeignKey(Collector)
 </s> add     owner = models.ForeignKey(Collector, models.CASCADE) </s> remove     owner = models.ForeignKey(Collector)
 </s> add     owner = models.ForeignKey(Collector, models.CASCADE)
    mother = models.ForeignKey(Parent, models.CASCADE, related_name='mothers_children')
    father = models.ForeignKey(Parent, models.CASCADE, related_name='fathers_children')
    school = models.ForeignKey(School, models.CASCADE)
      name = models.CharField(max_length=100)
  
  
  class Child(models.Model):
    mother = models.ForeignKey(Parent, models.CASCADE, related_name='mothers_children')
    father = models.ForeignKey(Parent, models.CASCADE, related_name='fathers_children')
    school = models.ForeignKey(School, models.CASCADE)
    mother = models.ForeignKey(Parent, models.CASCADE, related_name='mothers_children')
    father = models.ForeignKey(Parent, models.CASCADE, related_name='fathers_children')
    school = models.ForeignKey(School, models.CASCADE)
    mother = models.ForeignKey(Parent, models.CASCADE, related_name='mothers_children')
    father = models.ForeignKey(Parent, models.CASCADE, related_name='fathers_children')
    school = models.ForeignKey(School, models.CASCADE)
      name = models.CharField(max_length=100)
  
  
  @python_2_unicode_compatible
  class Poet(models.Model):
keep keep keep keep replace replace replace keep keep keep keep keep
 Fixed #21127 -- Started deprecation toward requiring on_delete for ForeignKey/OneToOneField 
tests/inline_formsets/models.py