code: def _assemble_single_output(
      self, estimator_params, base_score=0.0, split_idx=0
  ):
      estimators_ast = self._assemble_estimators(
          estimator_params, split_idx
      )
  
      tmp_ast = utils.apply_op_to_expressions(
          ast.BinNumOpType.ADD, *estimators_ast
      )
  
      if base_score != 0.0:
          tmp_ast = utils.apply_bin_op(
              ast.NumVal(base_score), tmp_ast, ast.BinNumOpType.ADD
          )
  
      result_ast = self._final_transform(tmp_ast)
  
      return result_ast
  
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 3 for calling the BaseBoostingAssembler obj's underlying member method code with example usage: obj._assemble_single_output(estimator_params, base_score, split_idx) and returns: result_ast