code: def _normalize_file_name(filename: str) -> str:
      supported_extensions = [".yaml"]
      if not version.base_at_least("1.2"):
          supported_extensions.append(".yml")
          if filename.endswith(".yml"):
              deprecation_warning(
                  "Support for .yml files is deprecated. Use .yaml extension for Hydra config files"
              )
      if not any(
          filename.endswith(ext) for ext in supported_extensions
      ):
          filename += ".yaml"
      return filename
  
imports: import re
  from abc import abstractmethod
  from dataclasses import dataclass
  from typing import Dict, List, Optional
  from omegaconf import Container
  from hydra import version
  from hydra._internal.deprecation_warning import deprecation_warning
  from hydra.core.default_element import InputDefault
  from hydra.core.object_type import ObjectType
  from hydra.errors import HydraException
  from hydra.plugins.plugin import Plugin
label_desc: Use image node_id 13 for calling the ConfigSource obj's underlying member method code with example usage: obj._normalize_file_name(filename) and returns: filename