docs: protected IPermissionSet cacheGet(IAuthorizationPrincipal principal)
              throws AuthorizationException {
          try {
              return (IPermissionSet)
                      EntityCachingService.getEntityCachingService()
                              .get(this.PERMISSION_SET_TYPE, principal.getPrincipalString());
          } catch (CachingException ce) {
              throw new AuthorizationException(
                      "Problem getting permissions for " + principal + " from cache", ce);
          }
      }