def test_allow_null(self):
        field = serializers.IntegerField(allow_null=True)
        output = field.run_validation(None)
        assert output is None
Print the result of applying a function on `node` and its children.
dataset/ETHPy150Open tomchristie/django-rest-framework/tests/test_fields.py/TestEmpty.test_allow_null--crossover with--dataset/ETHPy150Open enthought/traitsui/traitsui/tests/_tools.py/apply_on_children