code: def _fit_core(
      self,
      actual_anomalies: Sequence[TimeSeries],
      series: Sequence[TimeSeries],
  ):
      X = np.concatenate(
          [
              s.all_values(copy=False).reshape(len(s), -1)
              for s in series
          ],
          axis=0,
      )
  
      y = np.concatenate(
          [
              s.all_values(copy=False).reshape(len(s))
              for s in actual_anomalies
          ],
          axis=0,
      )
  
      self.model.fit(y=y, X=X)
      return self
  
file_path: darts/darts/ad/aggregators/ensemble_sklearn_aggregator.py
imports: from typing import Sequence
  import numpy
  from sklearn.ensemble import BaseEnsemble
  from darts import TimeSeries
  from darts.ad.aggregators.aggregators import FittableAggregator
  from darts.logging import raise_if_not
label_desc: Use image node_id 3 for calling the EnsembleSklearnAggregator obj's underlying member method code with example usage: obj._fit_core(actual_anomalies, series) and returns: self