code: def _bin_class_convert_output(self, expr, to_reuse=True):
      supported_objectives = {
          "binary": self._bin_class_sigmoid_transform,
          "custom": super()._single_convert_output,
      }
      if self.objective_name not in supported_objectives:
          raise ValueError(
              f"Unsupported objective function '{self.objective_name}'"
          )
      return supported_objectives[self.objective_name](expr)
  
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 5 for calling the LightGBMModelAssembler obj's underlying member method code with example usage: obj._bin_class_convert_output(expr, to_reuse) and returns: supported_objectives