code: def setUp(self):
      self.dirpath = tempfile.mkdtemp()
      import mlflow
  
      mlflow.set_tracking_uri(
          "sqlite:///" + self.dirpath + "/mlflow.sqlite"
      )
      mlflow.create_experiment(name="existing_experiment")
  
      self.mlflow_util = _MLflowLoggerUtil()
      self.tracking_uri = mlflow.get_tracking_uri()
  
imports: import os
  import shutil
  import tempfile
  import unittest
  from collections import namedtuple
  from unittest.mock import patch
  from mlflow.tracking import MlflowClient
  from ray._private.dict import flatten_dict
  from ray.train._internal.session import init_session, shutdown_session
  from ray.train._internal.storage import StorageContext
  from ray.air.integrations.mlflow import MLflowLoggerCallback, setup_mlflow, _NoopModule
  from ray.air._internal.mlflow import _MLflowLoggerUtil
label_desc: Use image node_id 1 for calling the MLflowUtilTest obj's underlying member method code with example usage: obj.setUp() without return types