code: def test_connection(
      self, onerror: Optional[Callable[[], Any]] = None
  ) -> None:
      try:
          with self.engine.connect() as conn:
              conn.exec_driver_sql("select 1")
      except Exception as exc:
          if callable(onerror):
              onerror()
          logger.exception(
              "Could not connect to the database. "
              "Check your database credentials and try again.",
              exc_info=False,
          )
          raise DvcException(
              "The database returned the following error"
          ) from exc
  
imports: import os
  from contextlib import contextmanager
  from dataclasses import dataclass
  from tempfile import NamedTemporaryFile
  from typing import TYPE_CHECKING, Any, Callable, Dict, Iterator, Optional, Union
  from sqlalchemy import create_engine
  from sqlalchemy.engine import make_url
  from sqlalchemy.exc import NoSuchModuleError
  from dvc import env
  from dvc.exceptions import DvcException
  from dvc.log import logger
  from dvc.types import StrOrBytesPath
  from dvc.utils import env2bool
label_desc: Use image node_id 1 for calling the Client obj's underlying member method code with example usage: obj.test_connection(onerror) without return types