def METHOD_NAME(self):
    sine_series = st(length=21, freq="MS")
    with pytest.raises(ValueError):
        fourtheta = FourTheta(
            model_mode=ModelMode.MULTIPLICATIVE,
            trend_mode=TrendMode.EXPONENTIAL,
            season_mode=SeasonalityMode.ADDITIVE,
            seasonality_period=12,
        )
        fourtheta.fit(sine_series)
    with pytest.raises(ValueError):
        theta = Theta(
            season_mode=SeasonalityMode.ADDITIVE,
            seasonality_period=12,
        )
        theta.fit(sine_series)