code: def test_repr(tmp_dir, scm, dvc):
      tmp_dir.dvc_gen("foo", "foo", commit="add foo")
  
      brancher = dvc.brancher([scm.get_rev()])
      rev = next(brancher)
      assert rev == "workspace"
      assert repr(Index(dvc)) == f"Index({dvc}, fs@{rev})"
  
      rev = next(brancher)
      assert rev == scm.get_rev()
      assert repr(Index(dvc)) == f"Index({dvc}, fs@{rev[:7]})"
  
imports: import os
  from itertools import chain
  import pytest
  from pygtrie import Trie
  from dvc.repo.index import Index
  from dvc.stage import Stage
label_desc: Use image node_id 2 for calling a global function with example usage: test_repr(tmp_dir, scm, dvc) without return types