docs: public void add(CmsAccessControlEntry entry) {
  
          CmsPermissionSetCustom p = m_permissions.get(entry.getPrincipal());
          if (p == null) {
              p = new CmsPermissionSetCustom();
              m_permissions.put(entry.getPrincipal(), p);
          }
          p.addPermissions(entry.getPermissions());
      }