def METHOD_NAME(self):
    self.runModule("g.region", res3=1, n=5, s=0, w=0, e=5, b=0, t=5)
    self.assertModule(
        "r3.gradient",
        input="test_map_2_ref",
        blocksize=[200, 2, 50],
        output=["test_null_grad_x", "test_null_grad_y", "test_null_grad_z"],
    )
    self.assertRaster3dFitsUnivar(
        raster="test_null_grad_x",
        reference=r3univar_test_nulls_grad_x,
        precision=1e-8,
    )
    self.assertRaster3dFitsUnivar(
        raster="test_null_grad_y",
        reference=r3univar_test_nulls_grad_y,
        precision=1e-8,
    )
    self.assertRaster3dFitsUnivar(
        raster="test_null_grad_z",
        reference=r3univar_test_nulls_grad_z,
        precision=1e-8,
    )