code: private void performSingleResourceNotification(
          CmsObject cms,
          String resName,
          boolean enableNotification,
          int notificationInterval,
          boolean modifySiblings)
      throws CmsException {
  
          List<CmsResource> resources = new ArrayList<CmsResource>();
          if (modifySiblings) {
              // modify all siblings of a resource
              resources = cms.readSiblings(resName, CmsResourceFilter.IGNORE_EXPIRATION);
          } else {
              // modify only resource without siblings
              resources.add(cms.readResource(resName, CmsResourceFilter.IGNORE_EXPIRATION));
          }
          Iterator<CmsResource> i = resources.iterator();
          while (i.hasNext()) {
              CmsResource resource = i.next();
              // lock resource if auto lock is enabled
              CmsLockActionRecord lockRecord = CmsLockUtil.ensureLock(cms, resource);
              try {
                  // write notification settings
                  writeProperty(
                      cms,
                      resource,
                      CmsPropertyDefinition.PROPERTY_NOTIFICATION_INTERVAL,
                      String.valueOf(notificationInterval));
                  writeProperty(
                      cms,
                      resource,
                      CmsPropertyDefinition.PROPERTY_ENABLE_NOTIFICATION,
                      String.valueOf(enableNotification));
              } finally {
                  if (lockRecord.getChange() == LockChange.locked) {
                      cms.unlockResource(resource);
                  }
              }
          }
      }
docs: Performs the notification operations on a single resource.<p>
  
  @param cms the CMS context
  @param resName the VFS path of the resource
  @param enableNotification if the notification is activated
  @param notificationInterval the notification interval in days
  @param modifySiblings flag indicating to include resource siblings
  
  @throws CmsException if the availability and notification operations fail