def validate_exclusive_use_of_hash_constraints!(conf, attribute)
      return unless is_hash?(conf)
      if conf.key?(:only) && conf.key?(:except)
        raise CookiesConfigError.new("#{attribute} cookie config is invalid, simultaneous use of conditional arguments `only` and `except` is not permitted.")
      end
    end
def validate_exclusive_use_of_hash_constraints!(conf, attribute)
      return unless is_hash?(conf)
      if conf.key?(:only) && conf.key?(:except)
        raise CookiesConfigError.new("#{attribute} cookie config is invalid, simultaneous use of conditional arguments `only` and `except` is not permitted.")
      end
    end
validate exclusive use of only or except but not both at the same time