def METHOD_NAME(self, basis):
    L = basis.nres
    if L < 32:
        pytest.skip()
    ell = 1
    sigma = L / 8
    im = gaussian_2d(L, sigma=sigma, dtype=basis.dtype)
    g2d = grid_2d(L)
    for trig_fun in (np.sin, np.cos):
        im1 = im * trig_fun(ell * g2d["phi"])
        coef = basis.expand(im1)
        ells = basis.indices()["ells"]
        energy_outside = np.sum(np.abs(coef[ells != ell]) ** 2)
        energy_total = np.sum(np.abs(coef) ** 2)
        energy_ratio = energy_outside / energy_total
        assert energy_ratio < 0.10