def _do_surface_dots_subset(intrad, rsurf, rmags, rref, refl, lsurf, rlens,
                            this_nn, cosmags, ws, volume, lut, n_fact, ch_type,
                            idx):
    products = _fast_sphere_dot_r0(
        intrad, rsurf, rmags, lsurf, rlens, this_nn, cosmags, None, ws,
        volume, lut, n_fact, ch_type).T
    if rref is not None:
        raise NotImplementedError  # we don't ever use this, isn't tested
        # vres = _fast_sphere_dot_r0(
        #     intrad, rref, rmags, refl, rlens, this_nn, cosmags, None, ws,
        #     volume, lut, n_fact, ch_type)
        # products -= vres
    return products
Returns at least one device (the root device).  All returned
dataset/ETHPy150Open mne-tools/mne-python/mne/forward/_lead_dots.py/_do_surface_dots_subset--crossover with--dataset/ETHPy150Open ClusterHQ/flocker/flocker/node/agents/test/test_ebs.py/FindAllocatedDeviceTests.test_returns_device_name_list