code: def test_subrepos(tmp_dir, scm, dvc, mocker):
      tmp_dir.scm_gen(
          {"dir": {"repo.txt": "file to confuse DVCFileSystem"}},
          commit="dir/repo.txt",
      )
  
      subrepo1 = tmp_dir / "dir" / "repo"
      subrepo2 = tmp_dir / "dir" / "repo2"
  
      for repo in [subrepo1, subrepo2]:
          make_subrepo(repo, scm)
  
      with subrepo1.chdir():
          subrepo1.dvc_gen(
              {"foo": "foo", "dir1": {"bar": "bar"}}, commit="FOO"
          )
      with subrepo2.chdir():
          subrepo2.dvc_gen(
              {"lorem": "lorem", "dir2": {"ipsum": "ipsum"}},
              commit="BAR",
          )
  
      dvc._reset()
      fs = DVCFileSystem(repo=dvc, subrepos=True)
  
      def assert_fs_belongs_to_repo(ret_val):
          method = fs.fs._get_repo
  
          def f(*args, **kwargs):
              r = method(*args, **kwargs)
              assert r.root_dir == ret_val.root_dir
              return r
  
          return f
  
      mock_subrepo1 = mocker.patch.object(
          fs.fs,
          "_get_repo",
          side_effect=assert_fs_belongs_to_repo(subrepo1.dvc),
      )
      assert fs.exists("dir/repo/foo") is True
      assert fs.exists("dir/repo/bar") is False
  
      assert fs.isfile("dir/repo/foo") is True
      assert fs.isfile("dir/repo/dir1/bar") is True
      assert fs.isfile("dir/repo/dir1") is False
  
      assert fs.isdir("dir/repo/dir1") is True
      assert fs.isdir("dir/repo/dir1/bar") is False
      assert fs.isdvc("dir/repo/foo") is True
      mocker.stop(mock_subrepo1)
  
      mock_subrepo2 = mocker.patch.object(
          fs.fs,
          "_get_repo",
          side_effect=assert_fs_belongs_to_repo(subrepo2.dvc),
      )
      assert fs.exists("dir/repo2/lorem") is True
      assert fs.exists("dir/repo2/ipsum") is False
  
      assert fs.isfile("dir/repo2/lorem") is True
      assert fs.isfile("dir/repo2/dir2/ipsum") is True
      assert fs.isfile("dir/repo2/dir2") is False
  
      assert fs.isdir("dir/repo2/dir2") is True
      assert fs.isdir("dir/repo2/dir2/ipsum") is False
      assert fs.isdvc("dir/repo2/lorem") is True
      mocker.stop(mock_subrepo2)
  
imports: import os
  import posixpath
  import shutil
  import pytest
  from fsspec.utils import tokenize
  from dvc.fs import localfs
  from dvc.fs.dvc import DVCFileSystem
  from dvc.testing.tmp_dir import make_subrepo
  from dvc_data.hashfile.build import build
  from dvc_data.hashfile.hash_info import HashInfo
label_desc: Use image node_id 19 for calling a global function with example usage: test_subrepos(tmp_dir, scm, dvc, mocker) and returns: f, r