code: def _fit(self, df: DataFrame) -> MultiIndexerModel:
      return MultiIndexerModel([i.fit(df) for i in self.indexers])
  
imports: from typing import List
  from synapse.ml.cyber.utils.spark_utils import DataFrameUtils, ExplainBuilder, HasSetInputCol, HasSetOutputCol
  from pyspark.ml import Estimator, Transformer
  from pyspark.ml.param.shared import HasInputCol, HasOutputCol, Param, Params
  from pyspark.sql import DataFrame, functions
label_desc: Use image node_id 2 for calling the MultiIndexer obj's underlying member method code with example usage: obj._fit(df) and returns: MultiIndexerModel