def METHOD_NAME(self):
    A = np.array([[1, 2, 3], [3, 2, 1]]).T
    C_D_inv = np.array([1, 1, 1])
    d = np.array([1, 2, 3])
    result, cov_error, image = de_lens.get_param_WLS(A, C_D_inv, d)
    npt.assert_almost_equal(result[0], 1, decimal=8)
    npt.assert_almost_equal(result[1], 0, decimal=8)
    npt.assert_almost_equal(image[0], d[0], decimal=8)
    result_new, cov_error_new, image_new = de_lens.get_param_WLS(
        A, C_D_inv, d, inv_bool=False
    )
    npt.assert_almost_equal(result_new[0], result[0], decimal=10)
    npt.assert_almost_equal(result_new[1], result[1], decimal=10)
    npt.assert_almost_equal(image_new[0], image[0], decimal=10)