def test_smooth_short_window_err(self):
        self.assertRaises(ValueError, smooth, self.x_20, window_len=2)
estspec: raise error in smooth(*a, window_len) if window_len too small
dataset/ETHPy150Open QuantEcon/QuantEcon.py/quantecon/tests/test_estspec.py/TestSmooth.test_smooth_short_window_err