def METHOD_NAME(brain_vol_files: list[str]) -> None:
    runner = CliRunner()
    with runner.isolated_filesystem():
        r = runner.invoke(
            linear_regression,
            [
                "--nidm_file_list",
                ",".join(brain_vol_files),
                "--ml",
                "fs_000008 = DX_GROUP + http://uri.interlex.org/ilx_0100400",
                "-o",
                "output.txt",
            ],
        )
        assert r.exit_code == 0
        out = Path("output.txt").read_text(encoding="utf-8")
    # check if model was read correctly
    assert "fs_000008 ~ ilx_0100400 + DX_GROUP" in out
    # check correct number of observations
    assert "No. Observations:                  53" in out
    # check model coefficients
    assert (
        "const          27.7816      4.378      6.345      0.000      18.988      36.576"
        in out
    )
    assert (
        "ilx_0100400    -0.1832      0.173     -1.061      0.294      -0.530       0.164"
        in out
    )
    assert (
        "DX_GROUP        3.4908      4.031      0.866      0.391      -4.605      11.587"
        in out
    )