code: public boolean actionCheckSiblings() {
  
          List<String> resourceList = getResourceList();
          String resourcePath;
          Iterator<String> itResourcePaths = resourceList.iterator();
          boolean foundSibling = false;
          while (itResourcePaths.hasNext()) {
              resourcePath = itResourcePaths.next();
              try {
                  foundSibling = recursiveCheckSiblings(resourcePath);
                  if (foundSibling) {
                      break; // shortcut
                  }
  
              } catch (CmsException e) {
                  LOG.error(Messages.get().getBundle(getLocale()).key(
                      Messages.ERR_UNDO_CHANGES_1,
                      new String[] {resourcePath}));
              }
  
          }
          return foundSibling;
      }
docs: Performs the check for siblings action and returns false in case of existence.<p>
  
  @return true if siblings are found.