def METHOD_NAME(tmp_path):
    # Fetch stopping power data files from data module
    tissue_path = get_file("NIST_PSTAR_tissue_equivalent.txt", directory=tmp_path)
    aluminum_path = get_file("NIST_PSTAR_aluminum.txt", directory=tmp_path)
    arr = np.loadtxt(tissue_path, skiprows=8)
    eaxis = arr[:, 0] * u.MeV
    tissue_density = 1.04 * u.g / u.cm**3
    tissue_equivalent = arr[:, 1] * u.MeV * u.cm**2 / u.g * tissue_density
    arr = np.loadtxt(aluminum_path, skiprows=8)
    aluminum_density = 2.7 * u.g / u.cm**3
    aluminum = arr[:, 1] * u.MeV * u.cm**2 / u.g * aluminum_density
    # Defines the order of layers that make up a single piece of
    # HDV2 film
    HDV2 = [
        Layer(12 * u.um, eaxis, tissue_equivalent, name="2-HDV2-active"),
        Layer(
            97 * u.um, eaxis, tissue_equivalent, name="2-HDV2-substrate", active=False
        ),
    ]
    # Define a film pack consisting of an aluminum filter followed by
    # 10 layers of HDV2
    layers = [*HDV2] * 10
    layers = [
        Layer(100 * u.um, eaxis, aluminum, name="1-aluminum filter", active=False),
        *layers,
    ]
    return Stack(layers)