docstr: Test cache dir path.
          
docstr_tok: ["Test","cache","dir","path","."]
code: def test_ais_binary(self):
      """Test cache dir path."""
      with mock.patch("shutil.which", lambda x: "/test/path/ais"):
          assert ais_binary() == "/test/path/ais"
  
      # Negative example: AIS binary cannot be found
      with mock.patch("shutil.which", lambda x: None), mock.patch(
          "os.path.isfile", lambda x: None
      ):
          with pytest.raises(RuntimeError):
              ais_binary()
  
file_path: NeMo/tests/utils/test_utils.py
imports: import os
  from unittest import mock
  import pytest
  from nemo import __version__
  from nemo.utils.data_utils import ais_binary, ais_endpoint_to_dir, bucket_and_object_from_uri, datastore_path_to_webdataset_url, is_datastore_path, resolve_cache_dir
label_desc: Use image node_id 5 for calling the TestDataUtils obj's underlying member method code with example usage: obj.test_ais_binary() without return types