code: def guess_strategy_type(file_name_or_ext):
      
      if '.' not in file_name_or_ext:
          ext = file_name_or_ext
      else:
          name, ext = os.path.splitext(file_name_or_ext)
      ext = ext.lstrip('.')
      file_type_map = get_file_type_map()
      return file_type_map.get(ext, None)
docs: Guess strategy type to use for file by extension.
  
      Args:
          file_name_or_ext: Either a file name with an extension or just
              an extension
  
      Returns:
          Strategy: Type corresponding to extension or None if there's no
              corresponding strategy type