def METHOD_NAME(hdv2_stack):
    energies = np.arange(1, 60, 1) * u.MeV
    deposition_curves = hdv2_stack.deposition_curves(energies, return_only_active=False)
    integral = np.sum(deposition_curves, axis=0)
    assert np.allclose(
        integral, 1.0
    ), "The integral over all layers for each particle species is not unity."