def METHOD_NAME():
    mg = RasterModelGrid((10, 10))
    mg.add_zeros("topographic__elevation", at="node")
    with pytest.raises(FieldError):
        DrainageDensity(
            mg,
            area_coefficient=1,
            slope_coefficient=1,
            area_exponent=1,
            slope_exponent=1,
            channelization_threshold=1,
        )