docs: private static boolean mayBrowse(
              final IAuthorizationPrincipal principal, final String targetId) {
          Validate.notNull(principal, "Cannot determine permissions for a null user.");
          Validate.notNull(targetId, "Cannot determine permissions on a null target.");
  
          return (principal.hasPermission(
                  IPermission.PORTAL_SUBSCRIBE, IPermission.PORTLET_BROWSE_ACTIVITY, targetId));
      }