code: public static void registerAVIMMessageType(Class<? extends AVIMTypedMessage> messageType) {
      AVIMMessageType type = messageType.getAnnotation(AVIMMessageType.class);
      if (type == null) {
        throw new IncompleteAnnotationException(AVIMMessageType.class, "type");
      }
      int messageTypeValue = type.type();
  
      messageTypesRepository.put(messageTypeValue, messageType);
      try {
        Method initializeMethod = messageType.getDeclaredMethod("computeFieldAttribute", Class.class);
        initializeMethod.setAccessible(true);
        initializeMethod.invoke(null, messageType);
      } catch (Exception e) {
        LOGGER.d("failed to initialize message Fields");
      }
    }
docs: 注册自定义的消息类型
  
  @param messageType