code: def validate_class_args(self, **kwargs):
      Schema(
          {
              Optional("optimize_mode"): self.choices(
                  "optimize_mode", "maximize", "minimize"
              ),
              Optional("start_step"): self.range(
                  "start_step", int, 0, 9999
              ),
          }
      ).validate(kwargs)
  
file_path: nni/nni/algorithms/hpo/medianstop_assessor.py
imports: from __future__ import annotations
  import logging
  from schema import Schema, Optional
  from typing_extensions import Literal
  from nni import ClassArgsValidator
  from nni.assessor import Assessor, AssessResult
  from nni.utils import extract_scalar_history
label_desc: Use image node_id 1 for calling the MedianstopClassArgsValidator obj's underlying member method code with example usage: obj.validate_class_args() without return types