class ActiveSupport::Messages::RotationCoordinator

def changing_configuration!
  if @codecs.any?
    raise <<~MESSAGE
      Cannot change #{self.class} configuration after it has already been applied.
      The configuration has been applied with the following salts:
      #{@codecs.keys.map { |salt| "- #{salt.inspect}" }.join("\n")}
    MESSAGE
  end
end