code: public String getCacheKey()
      {
          String ret = "noKey";
          UIClassification clazz = this;
          while (!clazz.isRoot()) {
              clazz = clazz.getParent();
          }
          final Field field = Field.get(clazz.getFieldId());
          if (field != null) {
              try {
                  ret = field.getCollection().getUUID().toString() + "-" + field.getName() + "-"
                                  + UIClassification.USERSESSIONKEY;
              } catch (final CacheReloadException e) {
                  UIClassification.LOG.error("Cannot generate CacheKey", e);
              }
          }
          return ret;
      }
docs: This method generates the Key for a UserAttribute by using the UUID of
  the Command and the given static part, so that for every StruturBrowser a
  unique key for expand etc, is created.
  
  @return String with the key