code: def _multi_class_sigmoid_transform(self, exprs):
      return ast.VectorVal(
          [
              self._bin_class_sigmoid_transform(expr, to_reuse=False)
              for expr in 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 LightGBMModelAssembler obj's underlying member method code with example usage: obj._multi_class_sigmoid_transform(exprs) and returns: ast