code: def supports_device(cls, device: str) -> bool:
      d = Device(device)
      if d.type == DeviceType.CPU:
          return True
      return False
  
file_path: onnx/onnx/test/test_backend_test.py
imports: import itertools
  import os
  import platform
  import unittest
  from typing import Any, Optional, Sequence, Tuple
  import numpy
  import onnx.backend.base
  import onnx.backend.test
  import onnx.shape_inference
  import onnx.version_converter
  from onnx import ModelProto, NodeProto, TensorProto
  from onnx.backend.base import Device, DeviceType
  from onnx.backend.test.runner import BackendIsNotSupposedToImplementIt
label_desc: Use image node_id 3 for calling the DummyBackend obj's underlying member method code with example usage: obj.supports_device(cls, device) and returns: False, True