def METHOD_NAME(petstore_dict):
    # to recap: "required": ["name","photoUrls"]
    petstore_spec = Spec.from_dict(petstore_dict)
    Pet = petstore_spec.definitions['Pet']
    pet_spec = petstore_spec.spec_dict['definitions']['Pet']
    pet = Pet(
        id=1,
        name='Fido',
        status=None,
        photoUrls=['wagtail.png', 'bark.png'],
        category=None,
        tags=None,
    )
    result = marshal_model(petstore_spec, pet_spec, pet)
    expected = {
        'id': 1,
        'name': 'Fido',
        'photoUrls': [
            'wagtail.png',
            'bark.png',
        ],
    }
    assert expected == result