code: def _fit(
      self,
      series: TimeSeries,
      future_covariates: Optional[TimeSeries] = None,
  ):
      super()._fit(series, future_covariates)
      self._assert_univariate(series)
      series = self.training_series
      self.model.fit(
          series.values(),
          X=future_covariates.values() if future_covariates else None,
      )
      return self
  
file_path: darts/darts/models/forecasting/auto_arima.py
imports: from typing import Optional
  from pmdarima import AutoARIMA
  from darts.logging import get_logger, raise_if
  from darts.models.forecasting.forecasting_model import FutureCovariatesLocalForecastingModel
  from darts.timeseries import TimeSeries
label_desc: Use image node_id 3 for calling the AutoARIMA obj's underlying member method code with example usage: obj._fit(series, future_covariates) and returns: self