code: def test_for_in_string(self):
      def test_strings(x):
          # type: (str) -> str
          reverse = ""
          for c in x:
              reverse = c + reverse
          return reverse
  
      self.checkScript(test_strings, ("hello",))
      self.checkScript(test_strings, ("",))
  
      def test_list_strings(x):
          # type: (List[str]) -> str
          result = ""
          for sub_str in x:
              result += sub_str
          return result
  
      self.checkScript(test_list_strings, (["hello", "world"],))
      self.checkScript(
          test_list_strings, (["hello", " ", "world", ""],)
      )
  
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 22 for calling the TestTyping obj's underlying member method code with example usage: obj.test_for_in_string() and returns: reverse, result