code: def unchecked_configuration_of(
      section: str,
      option: str,
      explicit_argument: Optional[T],
      fallback: T,
      *,
      deprecated_envvar: Optional[str] = None,
  ) -> Union[str, T]:
      if explicit_argument is not None:
          return explicit_argument
  
      envvar = "HAIL_" + section.upper() + "_" + option.upper()
      envval = os.environ.get(envvar, None)
      deprecated_envval = (
          None
          if deprecated_envvar is None
          else os.environ.get(deprecated_envvar)
      )
      if envval is not None:
          if deprecated_envval is not None:
              raise ValueError(
                  f"Value for configuration variable {section}/{option} is ambiguous "
                  f"because both {envvar} and {deprecated_envvar} are set (respectively "
                  f"to: {envval} and {deprecated_envval}."
              )
          return envval
      if deprecated_envval is not None:
          warnings.warn(
              f"Use of deprecated envvar {deprecated_envvar} for configuration variable "
              f"{section}/{option}. Please use {envvar} instead."
          )
          return deprecated_envval
  
      from_user_config = get_user_config().get(
          section, option, fallback=None
      )
      if from_user_config is not None:
          return from_user_config
  
      return fallback
  
file_path: hail/hail/python/hailtop/config/user_config.py
imports: from typing import Optional, Union, TypeVar
  import os
  import re
  import configparser
  import warnings
  from pathlib import Path
  from .variables import ConfigVariable
label_desc: Use image node_id 6 for calling a global function with example usage: unchecked_configuration_of(section, option, explicit_argument, fallback) and returns: fallback, explicit_argument, envval, deprecated_envval, from_user_config