'Simple test for uniform returns should generate 0 volatility'

def test_simple_volatility(self):

    nassets = 3
    ann_vol = AnnualizedVolatility()
    today = pd.Timestamp('2016', tz='utc')
    assets = np.arange(nassets, dtype=np.float64)
    returns = np.full((ann_vol.window_length, nassets), 0.004, dtype=np.float64)
    out = np.empty(shape=(nassets,), dtype=np.float64)
    ann_vol.compute(today, assets, out, returns, 252)
    expected_vol = np.zeros(nassets)
    np.testing.assert_almost_equal(out, expected_vol, decimal=8)
