MessageHeaders headers = message.getHeaders();
String sessionId = SimpMessageHeaderAccessor.getSessionId(headers);
SendToUser sendToUser = returnType.getMethodAnnotation(SendToUser.class);
if (sendToUser != null) {
boolean broadcast = sendToUser.broadcast();
String user = getUserName(message, headers);
if (user == null) {
if (sessionId == null) {
throw new MissingSessionUserException(message);
}