code: def create_results_dir(self):
      
      self._current_results_dir = self._cache_manager._results_dir_path(self.cache_key, stable=False)
      self._results_dir = self._cache_manager._results_dir_path(self.cache_key, stable=True)
  
      if not self.valid:
        # Clean the workspace for invalid vts.
        safe_mkdir(self._current_results_dir, clean=True)
  
      relative_symlink(self._current_results_dir, self._results_dir)
      self.ensure_legal()
docs: Ensure that the empty results directory and a stable symlink exist for these versioned targets.