def METHOD_NAME(brain_vol: BrainVol) -> None:
    project = brain_vol.cmu_test_project_uuid
    # ask for a field based on URI tail
    derivative_stats = brain_vol.restParser.run(
        brain_vol.files,
        f"/statistics/projects/{project}?fields=derivatives.fsl_000020",
    )
    assert "title" in derivative_stats
    assert "subjects" in derivative_stats
    assert len(derivative_stats["subjects"]) > 0
    for field in ["fsl_000020"]:
        assert field in derivative_stats
        for x in ["max", "min", "mean", "median", "standard_deviation"]:
            assert x in derivative_stats[field]
    # ask for a field based on URI tail
    derivative_stats = brain_vol.restParser.run(
        brain_vol.files,
        f"/statistics/projects/{project}?fields=derivatives.fsl_000020,instruments.AGE_AT_SCAN",
    )
    assert "title" in derivative_stats
    assert "subjects" in derivative_stats
    assert len(derivative_stats["subjects"]) > 0
    for field in ["fsl_000020", "AGE_AT_SCAN"]:
        assert field in derivative_stats
        for x in ["max", "min", "mean", "median", "standard_deviation"]:
            assert x in derivative_stats[field]