code: def prepare(
      cls, model: Any, device: str = "CPU", **kwargs: Any
  ) -> ReferenceEvaluatorBackendRep:
      # if isinstance(model, ReferenceEvaluatorBackendRep):
      #    return model
      if isinstance(model, ReferenceEvaluator):
          return ReferenceEvaluatorBackendRep(model)
      if isinstance(model, (str, bytes, ModelProto)):
          inf = cls.create_inference_session(model)
          return cls.prepare(inf, device, **kwargs)
      raise TypeError(f"Unexpected type {type(model)} for model.")
  
imports: import os
  import platform
  import sys
  import unittest
  from typing import Any
  import numpy
  import version_utils
  import onnx.backend.base
  import onnx.backend.test
  import onnx.shape_inference
  import onnx.version_converter
  from onnx import ModelProto
  from onnx.backend.base import Device, DeviceType
  from onnx.reference import ReferenceEvaluator
label_desc: Use image node_id 4 for calling the ReferenceEvaluatorBackend obj's underlying member method code with example usage: obj.prepare(cls, model, device) and returns: ReferenceEvaluatorBackendRep, cls