code: def pytest_sessionstart(session):
      if uri := MLFLOW_TRACKING_URI.get():
          click.echo(
              click.style(
                  (
                      f"Environment variable {MLFLOW_TRACKING_URI} is set to {uri!r}, "
                      "which may interfere with tests."
                  ),
                  fg="red",
              )
          )
  
imports: import json
  import os
  import posixpath
  import shutil
  import subprocess
  import sys
  import click
  import pytest
  from mlflow.environment_variables import _MLFLOW_TESTING, MLFLOW_TRACKING_URI
  from mlflow.version import VERSION
  from tests.helper_functions import get_safe_port
label_desc: Use image node_id 4 for calling a global function with example usage: pytest_sessionstart(session) without return types