code: def _bin_class_convert_output(self, expr, to_reuse=True):
      return ast.SigmoidExpr(expr, to_reuse=to_reuse)
  
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 8 for calling the BaseBoostingAssembler obj's underlying member method code with example usage: obj._bin_class_convert_output(expr, to_reuse) and returns: ast