code: protected Set<String> updateTreePath(QPath prevRootPath, QPath newRootPath, Set<String> idsToSkip)
     {
        return caller.updateTreePath(prevRootPath, newRootPath, idsToSkip);
     }
docs: Check all items in cache if it is a descendant of the previous root path, and if so update the path according
  the new root path.
  
  @param prevRootPath previous root path
  @param newRootPath new root path
  @param idsToSkip set of ids to skip, this is needed to avoid modifying the path twice in case of an OrderBefore
  @return the ids to skip for the next operation