code: def testPathSeparator(self):
      # In nix systems, path separator would be the same as that of CNS/GCS
      # making it hard to tell if something went wrong.
      self.stubs.Set(os, "sep", "#")
  
      self.assertEqual(io_wrapper.PathSeparator("/tmp/foo"), "#")
      self.assertEqual(io_wrapper.PathSeparator("tmp/foo"), "#")
      self.assertEqual(io_wrapper.PathSeparator("gs://foo"), "/")
      self.assertEqual(io_wrapper.PathSeparator("s3://foo"), "/")
  
imports: import os
  import tempfile
  import tensorflow
  from tensorboard.backend.event_processing import io_wrapper
label_desc: Use image node_id 3 for calling the IoWrapperTest obj's underlying member method code with example usage: obj.testPathSeparator() without return types