code: def test_optional_none(self):
      def optional_test_none(x: Any):
          assert torch.jit.isinstance(x, Optional[torch.Tensor])
          # assert torch.jit.isinstance(x, Optional[str])
          # TODO: above line in eager will evaluate to True while in
          #       the TS interpreter will evaluate to False as the
          #       first torch.jit.isinstance refines the 'None' type
  
      x = None
      self.checkScript(optional_test_none, (x,))
  
imports: import os
  import sys
  import torch
  import warnings
  from typing import List, Any, Dict, Tuple, Optional
  from torch.testing._internal.jit_utils import JitTestCase
label_desc: Use image node_id 11 for calling the TestIsinstance obj's underlying member method code with example usage: obj.test_optional_none() without return types