docs: protected final String getPrimaryUserAttribute(PortletRequest request) {
          final PortletPreferences preferences = request.getPreferences();
          @SuppressWarnings("unchecked")
          final Map<String, String> userAttributes = (Map<String, String>)request.getAttribute(PortletRequest.USER_INFO);
          
          final String[] attributeNames = preferences.getValues(primaryUserAttributesPreference, new String[0]);
          for (final String attributeName : attributeNames) {
              final String emplid = userAttributes.get(attributeName);
              if (StringUtils.isNotEmpty(emplid)) {
                  if (logger.isDebugEnabled()) {
                      logger.debug("Found emplid '" + emplid + "' for under attribute: " + attributeName);
                  }
                  
                  return emplid;
              }
          }
          
          logger.warn("Could not find a value for any of the user attributes " + Arrays.toString(attributeNames) + " specified by preference: " + primaryUserAttributesPreference);
          
          throw new AccessDeniedException("No primary attribute found in attributes: " + Arrays.toString(attributeNames));
      }