async def METHOD_NAME(self, client):
    input_ap_true = PetAPTrue(
        id = 1,
        name = 'Puppy',
        additional_properties = {
            'birthdate': '2017-12-13T02:29:51Z',
            'complexProperty': {
                'color': 'Red'
            }
        }
    )
    output_ap_true = await client.pets.create_ap_true(input_ap_true)
    assert output_ap_true.additional_properties['birthdate'] ==  '2017-12-13T02:29:51Z'