code: def test_list_artifacts_empty(ftp_mock):
      repo = FTPArtifactRepository("ftp://test_ftp/some/path")
  
      repo.get_ftp_client = MagicMock()
      call_mock = MagicMock(return_value=ftp_mock)
      repo.get_ftp_client.return_value = MagicMock(__enter__=call_mock)
  
      ftp_mock.nlst = MagicMock(return_value=[])
      assert repo.list_artifacts() == []
      ftp_mock.nlst.assert_called_once_with("/some/path")
  
imports: import ftplib
  import posixpath
  from ftplib import FTP
  from unittest.mock import MagicMock
  import pytest
  from mlflow.store.artifact.artifact_repository_registry import get_artifact_repository
  from mlflow.store.artifact.ftp_artifact_repo import FTPArtifactRepository
label_desc: Use image node_id 3 for calling a global function with example usage: test_list_artifacts_empty(ftp_mock) without return types