code: def test_param_keys_no_params(dvc):
      index = Index.from_repo(dvc)
      assert index.param_keys == {"repo": set()}
  
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 18 for calling a global function with example usage: test_param_keys_no_params(dvc) without return types