class MBMessageResolversImpl implements MBMessageResolvers {

    @Override
    public DataFetcher<MBMessage> updateMBMessageDataFetcher() {
        return environment -> {
            long userId = util.getLongArg(environment, "userId", util.getDefaultUserId());
            long messageId = util.getLongArg(environment, "messageId");
            String subject = util.getStringArg(environment, "subject");
            String body = util.getStringArg(environment, "body");
            double priority = util.getDoubleArg(environment, "priority");
            boolean allowPingbacks = util.getBooleanArg(environment, "allowPingbacks");
            ServiceContext serviceContext = new ServiceContext();

            return mbMessageLocalService.updateMessage(
                    userId,
                    messageId,
                    subject,
                    body,
                    null,
                    null,
                    priority,
                    allowPingbacks,
                    serviceContext);
        };
    }

}