code: def enable_propagation() -> None:
      """Enable propagation of the library log outputs.
  
      Please disable the Optuna's default handler to prevent double logging if the root logger has
      been configured.
  
      Example:
  
          Propagate all log output to the root logger in order to save them to the file.
  
          .. testsetup::
  
              def objective(trial):
                  x = trial.suggest_float("x", -100, 100)
                  y = trial.suggest_categorical("y", [-1, 0, 1])
                  return x**2 + y
  
          .. testcode::
  
              import optuna
              import logging
  
              logger = logging.getLogger()
  
              logger.setLevel(logging.INFO)  # Setup the root logger.
              logger.addHandler(logging.FileHandler("foo.log", mode="w"))
  
              optuna.logging.enable_propagation()  # Propagate logs to the root logger.
              optuna.logging.disable_default_handler()  # Stop showing logs in sys.stderr.
  
              study = optuna.create_study()
  
              logger.info("Start optimization.")
              study.optimize(objective, n_trials=10)
  
              with open("foo.log") as f:
                  assert f.readline().startswith("A new study created")
                  assert f.readline() == "Start optimization.\\n"
  
      """
  
      _configure_library_root_logger()
      _get_library_root_logger().propagate = True
  
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 13 for calling a global function with example usage: enable_propagation() without return types