def _get_predict_start(self, start, dynamic):
        # do some defaults
        method = getattr(self, 'method', 'mle')
        k_ar = getattr(self, 'k_ar', 0)
        k_diff = getattr(self, 'k_diff', 0)
        if start is None:
            if 'mle' is not method and not dynamic:
                start = 0
            else:
                start = k_ar
            self._set_predict_start_date(start)  # else it's done in super
        elif isinstance(start, int):
            start = super(ARMA, self)._get_predict_start(start)
        else:  # should be on a date
            #elif 'mle' not in method or dynamic: # should be on a date
            start = _validate(start, k_ar, k_diff, self.data.dates,
                              method)
            start = super(ARMA, self)._get_predict_start(start)
        _check_arima_start(start, k_ar, k_diff, method, dynamic)
        return start
dataset/ETHPy150Open statsmodels/statsmodels/statsmodels/tsa/arima_model.py/ARMA._get_predict_start/operator `in` -> `is not`