code: def transfer(self, from_odb, to_odb):
      from dvc.fs import HTTPFileSystem, LocalFileSystem
      from dvc.fs.callbacks import TqdmCallback
  
      from_fs = from_odb.fs
      to_fs = to_odb.fs
      func = fs.generic.log_exceptions(fs.generic.copy)
      runs = from_fs.join(from_odb.path, "runs")
  
      http_odb = next(
          (
              odb
              for odb in (from_odb, to_odb)
              if isinstance(odb.fs, HTTPFileSystem)
          ),
          None,
      )
      if http_odb:
          path = http_odb.path
          message = (
              f"run-cache is not supported for http filesystem: {path}"
          )
          raise RunCacheNotSupported(message)
  
      ret: List[Tuple[str, str]] = []
      if not from_fs.exists(runs):
          return ret
  
      for src in from_fs.find(runs):
          rel = from_fs.relpath(src, from_odb.path)
          if not isinstance(to_fs, LocalFileSystem):
              rel = from_fs.as_posix(rel)
  
          dst = to_fs.join(to_odb.path, rel)
          key = to_fs.parent(dst)
          # check if any build cache already exists for this key
          # TODO: check if MaxKeys=1 or something like that applies
          # or otherwise this will take a lot of time!
          if to_fs.exists(key) and first(to_fs.find(key)):
              continue
  
          src_name = from_fs.name(src)
          parent_name = from_fs.name(from_fs.parent(src))
          with TqdmCallback(
              desc=src_name,
              bytes=True,
          ) as cb:
              func(from_fs, src, to_fs, dst, callback=cb)
          ret.append((parent_name, src_name))
      return ret
  
imports: import os
  from contextlib import contextmanager
  from typing import TYPE_CHECKING, List, Optional, Tuple
  from funcy import first
  from dvc import fs
  from dvc.config import RemoteConfigError
  from dvc.exceptions import CollectCacheError, DvcException
  from dvc.log import logger
  from dvc.utils import dict_sha256, relpath
label_desc: Use image node_id 11 for calling the StageCache obj's underlying member method code with example usage: obj.transfer(from_odb, to_odb) and returns: ret, ret