def METHOD_NAME(self):
    nxs = [1, 3]
    nys = [1, 3]
    for nx in nxs:
        for ny in nys:
            g = pp.CartGrid([nx, ny], physdims=[1, 1])
            g.compute_geometry()
            k = pp.SecondOrderTensor(np.ones(g.num_cells))
            robin_weight = 1.5
            bot = g.face_centers[1] < 1e-10
            top = g.face_centers[1] > 1 - 1e-10
            dir_ind = np.ravel(np.argwhere(top))
            rob_ind = np.ravel(np.argwhere(bot))
            names = ["dir"] * len(dir_ind) + ["rob"] * len(rob_ind)
            bnd_ind = np.hstack((dir_ind, rob_ind))
            bnd = pp.BoundaryCondition(g, bnd_ind, names)
            p_bound = 1
            rob_bound = 1
            C = (rob_bound - robin_weight * p_bound) / (robin_weight - p_bound)
            u_ex = C * g.face_normals[1]
            p_ex = C * (1 - g.cell_centers[1]) + p_bound
            self.solve_robin(
                g,
                k,
                bnd,
                robin_weight,
                p_bound,
                rob_bound,
                dir_ind,
                rob_ind,
                p_ex,
                u_ex,
            )