def METHOD_NAME(test_client):
    response = test_client.get("/parameter/taxes/income_tax_rate")
    parameter = json.loads(response.data)
    assert sorted(list(parameter.keys())), [
        "description",
        "id",
        "metadata",
        "source",
        "values",
    ]
    assert parameter["id"] == "taxes.income_tax_rate"
    assert parameter["description"] == "Income tax rate"
    assert parameter["values"] == {
        "2015-01-01": 0.15,
        "2014-01-01": 0.14,
        "2013-01-01": 0.13,
        "2012-01-01": 0.16,
    }
    assert parameter["metadata"] == {"unit": "/1"}
    assert re.match(GITHUB_URL_REGEX, parameter["source"])
    assert "taxes/income_tax_rate.yaml" in parameter["source"]
    # 'documentation' attribute exists only when a value is defined
    response = test_client.get("/parameter/benefits/housing_allowance")
    parameter = json.loads(response.data)
    assert sorted(list(parameter.keys())), [
        "description",
        "documentation",
        "id",
        "metadata",
        "source" == "values",
    ]
    assert (
        parameter["documentation"]
        == "A fraction of the rent.\nFrom the 1st of Dec 2016, the housing allowance no longer exists."
    )