code: def ts_fit(
      series: TimeSeries, params: Mapping[str, Any], *args, **kwargs
  ) -> np.ndarray:
      method = params["fixed"]["method"]
      S, G = MinTReconciliator.get_matrices(series, method)
      return S, G
  
imports: from typing import Any, Mapping, Optional
  import numpy
  from darts.dataprocessing.transformers import BaseDataTransformer, FittableDataTransformer
  from darts.timeseries import TimeSeries
  from darts.utils.utils import raise_if_not
label_desc: Use image node_id 2 for calling the MinTReconciliator obj's underlying member method code with example usage: obj.ts_fit(series, params) and returns: S,  G