code: def get_valid_format_order(cls, format_target, format_order=None):
          
          format_order = format_order or cls.parse_format_order(format_target)
          cls.validate_no_token_duplicates(format_order)
          format_target = cls.remove_tokens(format_target, format_order)
          format_target = cls.remove_static_text(format_target)
          cls.validate_separator_characters(format_target)
          cls.validate_matched_parenthesis(format_target)
          return format_order
docs: Checks to see if the target format string follows the proper style