code: def fso_symlink(self, source, link_name):
      'overlays os.symlink()'
      path = self.deref(link_name, to_parent=True)
      if self._exists(path):
        raise OSError(17, 'File exists')
      self._addentry(OverlayEntry(self, path, stat.S_IFLNK, source)f fso_symlink(self, source, link_name):
      'overlays os.symlink()'
      path = self.deref(link_name, to_parent=True)
      if self._exists(path):
        raise OSError(17, 'File exists')
      self._addentry(OverlayEntry(self, path, stat.S_IFLNK, source))
docs: overlays os.symlink()