code: def test_opset_fallback(self):
      class MyModule(Module):
          def forward(self, x):
              return torch.isnan(x)
  
      ops = [{"op_name": "IsNaN"}]
      ops = {9: ops, 10: ops}
      x = torch.tensor([1.0, float("nan"), 2.0])
      check_onnx_opsets_operator(
          MyModule(), x, ops, opset_versions=[9, 10]
      )
  
imports: import io
  import itertools
  import onnx
  import pytorch_test_common
  import torch
  import torch.onnx
  from torch.nn import Module
  from torch.onnx import producer_name, producer_version
  from torch.onnx._globals import GLOBALS
  from torch.testing._internal import common_utils
label_desc: Use image node_id 1 for calling the TestONNXOpset obj's underlying member method code with example usage: obj.test_opset_fallback() and returns: torch