docs: public static String permissionTargetIdForPortletDefinition(
              final IPortletDefinition portletDefinition) {
  
          Validate.notNull(
                  portletDefinition,
                  "Cannot compute permission target ID for a null portlet definition.");
  
          final String portletPublicationId =
                  portletDefinition.getPortletDefinitionId().getStringId();
  
          return IPermission.PORTLET_PREFIX.concat(portletPublicationId);
      }