code: def _assemble_multi_class_output(self, estimator_params):
      # Multi-class output is calculated based on discussion in
      # https://github.com/dmlc/xgboost/issues/1746#issuecomment-295962863
      # and the enhancement to support boosted forests in XGBoost.
      splits = _split_estimator_params_by_classes(
          estimator_params,
          self._output_size,
          self.multiclass_params_seq_len,
      )
  
      base_score = self._base_score
      exprs = [
          self._assemble_single_output(
              e, base_score=base_score, split_idx=i
          )
          for i, e in enumerate(splits)
      ]
  
      return self._multi_class_convert_output(exprs)
  
imports: import json
  import math
  import numpy
  from m2cgen import ast
  from m2cgen.assemblers import utils
  from m2cgen.assemblers.base import ModelAssembler
  from m2cgen.assemblers.linear import _linear_to_ast
label_desc: Use image node_id 4 for calling the BaseBoostingAssembler obj's underlying member method code with example usage: obj._assemble_multi_class_output(estimator_params) and returns: self