code: def main():
      tracking_uri = get_tracking_uri()
      assert (
          tracking_uri
      ), f"Environment variable {MLFLOW_TRACKING_URI} must be set"
      get_database_dialect(
          tracking_uri
      )  # Ensure `tracking_uri` is a database URI
      mlflow.set_tracking_uri(tracking_uri)
      initialize_database()
      schema_path = get_schema_path(tracking_uri)
      existing_schema = schema_path.read_text()
      latest_schema = dump_schema(tracking_uri)
      if not schema_equal(existing_schema, latest_schema):
          schema_path.write_text(latest_schema)
  
imports: import difflib
  import re
  from collections import namedtuple
  from pathlib import Path
  import pytest
  import sqlalchemy
  from packaging.version import Version
  from sqlalchemy import create_engine
  from sqlalchemy.schema import CreateTable, MetaData
  import mlflow
  from mlflow.environment_variables import MLFLOW_TRACKING_URI
label_desc: Use image node_id 12 for calling a global function with example usage: main() without return types