def METHOD_NAME(tmp_path):
    population_size = 4
    _cohortextractor(
        study="test_params",
        args=[
            "generate_cohort",
            "--expectations-population",
            str(population_size),
            "--output-file",
            tmp_path / "results_with_params.csv",
            "--param",
            "age_suffix=one",
            "--param",
            "sex_suffix",
            "=",
            "two",
        ],
    )
    with open(tmp_path / "results_with_params.csv") as f:
        contents = list(csv.reader(f))
    assert len(contents) == population_size + 1
    assert set(contents[0]) == {"patient_id", "age_one", "sex_two"}