def METHOD_NAME():
    mg = RasterModelGrid((10, 10))
    mg.add_zeros("topographic__elevation", at="node")
    noise = np.random.rand(mg.size("node"))
    mg.at_node["topographic__elevation"] += noise
    fr = FlowAccumulator(mg, flow_director="D8")
    fr.run_one_step()
    mask = np.zeros(len(mg.at_node["topographic__elevation"]), dtype=np.uint8)
    mask[np.where(mg.at_node["drainage_area"] > 5)] = 1
    with pytest.warns(UserWarning):
        DrainageDensity(mg, channel__mask=mask, area_coefficient=1)
    with pytest.warns(UserWarning):
        DrainageDensity(mg, channel__mask=mask, slope_coefficient=1)
    with pytest.warns(UserWarning):
        DrainageDensity(mg, channel__mask=mask, area_exponent=1)
    with pytest.warns(UserWarning):
        DrainageDensity(mg, channel__mask=mask, slope_exponent=1)
    with pytest.warns(UserWarning):
        DrainageDensity(mg, channel__mask=mask, channelization_threshold=1)