class_docstr: Syncer using a background process for asynchronous file transfer.
class_docstr_tok: ["Syncer","using","a","background","process","for","asynchronous","file","transfer","."]
code: def _sync_down_command(
      self, uri: str, local_path: str
  ) -> Tuple[Callable, Dict]:
      raise NotImplementedError
  
imports: import abc
  import logging
  import threading
  import time
  import traceback
  import warnings
  from dataclasses import dataclass
  from typing import Any, Callable, Dict, List, Optional, Tuple, Union
  from ray._private.thirdparty.tabulate.tabulate import tabulate
  from ray.train.constants import _DEPRECATED_VALUE
  from ray.util import log_once
  from ray.util.annotations import PublicAPI
  from ray.widgets import Template
label_desc: Use image node_id 7 for calling the _BackgroundSyncer obj's underlying member method code with example usage: obj._sync_down_command(uri, local_path) without return types