def METHOD_NAME():
    # testing against R CircStats package
    data = np.array([190.18, 175.48, 155.95, 217.83, 156.36]) * u.deg
    # answer was obtained through R CircStats function v0.test(x)
    answer = 0.9994725
    assert_allclose(answer, vtest(data), atol=1e-5)