          """
          parent = ParentModel.objects.create(name1='parent name')
          associate = AssociatedModel.objects.create(name='hello', ref=parent)
          serializer = AssociatedModelSerializer(associate)
          assert set(serializer.data.keys()) == {'name', 'ref'}
  
      def test_data_is_valid_without_parent_ptr(self):
          """
          Assert that the pointer to the parent table is not a required field
          for input data
 
</s> remove         assert set(serializer.data.keys()) == {'name1', 'name2', 'id'}
 </s> add         assert set(serializer.data) == {'name1', 'name2', 'id'} </s> remove         assert list(response.data['actions'].keys()) == ['PUT']
 </s> add         assert list(response.data['actions']) == ['PUT'] </s> remove         assert list(request.POST.keys()) == []
        assert list(request.FILES.keys()) == ['upload']
 </s> add         assert list(request.POST) == []
        assert list(request.FILES) == ['upload'] </s> remove         assert list(serializer.validated_data.keys()) == []
 </s> add         assert list(serializer.validated_data) == [] </s> remove         assert list(serializer.validated_data.keys()) == ['message']
 </s> add         assert list(serializer.validated_data) == ['message']
        assert set(serializer.data) == {'name', 'ref'}
          """
          parent = ParentModel.objects.create(name1='parent name')
          associate = AssociatedModel.objects.create(name='hello', ref=parent)
          serializer = AssociatedModelSerializer(associate)
        assert set(serializer.data) == {'name', 'ref'}
  
      def test_data_is_valid_without_parent_ptr(self):
          """
          Assert that the pointer to the parent table is not a required field
          for input data
keep keep keep keep replace keep keep keep keep keep
 Perfer iter(dict) over iter(dict.keys()) (#5736)

Calling dict.keys() is unnecessary. The two are functionally equivalent
on modern Pythons.

Inspired by Lennart Regebro's talk "Prehistoric Patterns in Python" from
PyCon 2017.

https://www.youtube.com/watch?v=V5-JH23Vk0I 
tests/test_multitable_inheritance.py