code: def enable_default_handler() -> None:
      """Enable the default handler of the Optuna's root logger.
  
      Please refer to the example shown in :func:`~optuna.logging.disable_default_handler()`.
      """
  
      _configure_library_root_logger()
  
      assert _default_handler is not None
      _get_library_root_logger().addHandler(_default_handler)
  
imports: from __future__ import annotations
  import logging
  from logging import CRITICAL
  from logging import DEBUG
  from logging import ERROR
  from logging import FATAL
  from logging import INFO
  from logging import WARN
  from logging import WARNING
  import os
  import sys
  import threading
  import colorlog
label_desc: Use image node_id 11 for calling a global function with example usage: enable_default_handler() without return types