code: def test_save(tmp_dir, dvc, run_copy):
      run_cache_dir = dvc.stage_cache.cache_dir
      assert not os.path.exists(run_cache_dir)
  
      tmp_dir.gen("foo", "foo")
      stage = run_copy("foo", "bar", name="copy-foo-bar")
      assert _recurse_count_files(run_cache_dir) == 1
      assert dvc.stage_cache._load(stage)
  
file_path: dvc/tests/func/test_run_cache.py
imports: import os
  import pytest
  from funcy import first
  from dvc.dvcfile import LOCK_FILE
  from dvc.stage.cache import RunCacheNotSupported, _get_stage_hash
  from dvc.utils.fs import remove
label_desc: Use image node_id 4 for calling a global function with example usage: test_save(tmp_dir, dvc, run_copy) without return types