docs: private CmsLock getSiblingsLock(List<CmsResource> siblings, String resourcename) {
  
          for (int i = 0; i < siblings.size(); i++) {
              CmsResource sibling = siblings.get(i);
              CmsLock exclusiveLock = getDirectLock(sibling.getRootPath());
              if (exclusiveLock != null) {
                  // a sibling is already locked
                  return internalSiblingLock(exclusiveLock, resourcename);
              }
          }
          // no locked siblings found
          return null;
  
      }