code: def create_evaluator(
      self, params: list[problem.Var]
  ) -> problem.Evaluator:
      return WFGEvaluator(params)
  
imports: from __future__ import annotations
  import math
  import sys
  import numpy
  import shape_functions
  import transformation_functions
  from kurobako import problem
label_desc: Use image node_id 2 for calling the WFGProblem obj's underlying member method code with example usage: obj.create_evaluator(params) and returns: WFGEvaluator