code: def test_create_sqlalchemy_engine_null_pool(monkeypatch):
      monkeypatch.setenv("MLFLOW_SQLALCHEMYSTORE_POOLCLASS", "NullPool")
      with mock.patch("sqlalchemy.create_engine") as mock_create_engine:
          utils.create_sqlalchemy_engine("mydb://host:port/")
          mock_create_engine.assert_called_once_with(
              "mydb://host:port/",
              pool_pre_ping=True,
              poolclass=NullPool,
          )
  
file_path: mlflow/tests/store/db/test_utils.py
imports: from unittest import mock
  import pytest
  from sqlalchemy.pool import NullPool
  from sqlalchemy.pool.impl import QueuePool
  from mlflow.store.db import utils
label_desc: Use image node_id 2 for calling a global function with example usage: test_create_sqlalchemy_engine_null_pool(monkeypatch) without return types