code: def test_optional_refinement(self):
      @torch.jit.script
      def test_if_none_assignment(x):
          # type: (Optional[int]) -> int
          if x is None:
              x = 1
          return x + 1
  
      self.assertEqual(test_if_none_assignment(1), 2)
  
imports: import os
  import sys
  import torch
  from torch.testing._internal.jit_utils import JitTestCase, make_global
  from torch.testing._internal.common_utils import IS_WINDOWS
  from collections import namedtuple
  from typing import List, Tuple, Dict, NamedTuple
label_desc: Use image node_id 33 for calling the TestTyping obj's underlying member method code with example usage: obj.test_optional_refinement() and returns: unknown