docs: def _backup_dir_item(self, dir_path, process_bar):
          """
          Backup one dir item
  
          :param dir_path: filesystem_walk.DirEntryPath() instance
          """
          self.path_helper.set_src_filepath(dir_path)
          if self.path_helper.abs_src_filepath is None:
              self.total_errored_items += 1
              log.info("Can't backup %r", dir_path)
  
          # self.summary(no, dir_path.stat.st_mtime, end=" ")
          if dir_path.is_symlink:
              self.summary("TODO Symlink: %s" % dir_path)
              return
  
          if dir_path.resolve_error is not None:
              self.summary("TODO resolve error: %s" % dir_path.resolve_error)
              pprint_path(dir_path)
              return
  
          if dir_path.different_path:
              self.summary("TODO different path:")
              pprint_path(dir_path)
              return
  
          if dir_path.is_dir:
              self.summary("TODO dir: %s" % dir_path)
          elif dir_path.is_file:
              # self.summary("Normal file: %s", dir_path)
  
              file_backup = FileBackup(dir_path, self.path_helper, self.backup_run)
              old_backup_entry = self.fast_compare(dir_path)
              if old_backup_entry is not None:
                  # We can just link the file from a old backup
                  file_backup.fast_deduplication_backup(old_backup_entry, process_bar)
              else:
                  file_backup.deduplication_backup(process_bar)
  
              assert file_backup.fast_backup is not None, dir_path.path
              assert file_backup.file_linked is not None, dir_path.path
  
              file_size = dir_path.stat.st_size
              if file_backup.file_linked:
                  # os.link() was used
                  self.total_file_link_count += 1
                  self.total_stined_bytes += file_size
              else:
                  self.total_new_file_count += 1
                  self.total_new_bytes += file_size
  
              if file_backup.fast_backup:
                  self.total_fast_backup += 1
          else:
              self.summary("TODO:" % dir_path)
              pprint_path(dir_path)