docs: private void saveAddInfo(String key, String value) {
  
          int pos = key.indexOf("@");
  
          String className = "";
          if (pos > -1) {
              className = key.substring(pos + 1);
              key = key.substring(0, pos);
          }
  
          if (CmsStringUtil.isEmptyOrWhitespaceOnly(value)) {
              m_user.deleteAdditionalInfo(key);
              return;
          }
  
          if (pos < 0) {
              m_user.setAdditionalInfo(key, value);
              return;
          }
  
          Class<?> clazz;
          try {
              // try the class name
              clazz = Class.forName(className);
          } catch (Throwable e) {
              try {
                  // try the class in the java.lang package
                  clazz = Class.forName(Integer.class.getPackage().getName() + "." + className);
              } catch (Throwable e1) {
                  clazz = String.class;
              }
          }
          m_user.setAdditionalInfo(key, CmsDataTypeUtil.parse(value, clazz));
      }