code: def test_open_dirty_hash(tmp_dir, dvc):
      tmp_dir.dvc_gen("file", "file")
      (tmp_dir / "file").write_text("something")
  
      fs = DataFileSystem(index=dvc.index.data["repo"])
      with fs.open("file", "r") as fobj:
          # NOTE: Unlike DVCFileSystem, DataFileSystem should not
          # be affected by a dirty workspace.
          assert fobj.read() == "file"
  
imports: import posixpath
  import shutil
  import pytest
  import dvc_data
  from dvc.fs import localfs
  from dvc.fs.data import DataFileSystem
  from dvc.utils.fs import remove
  from dvc_data.hashfile.build import build
  from dvc_data.hashfile.hash_info import HashInfo
label_desc: Use image node_id 4 for calling a global function with example usage: test_open_dirty_hash(tmp_dir, dvc) without return types