code: private String getCacheKeyForCurrentProject(CmsObject cms, String rootPath) {
  
          // check the project
          boolean project = (cms != null) ? cms.getRequestContext().getCurrentProject().isOnlineProject() : false;
          return getCacheKey(rootPath, project);
      }
docs: Returns a cache key for the given root path based on the status
  of the given CmsObject.<p>
  
  @param cms the cms context
  @param rootPath the filename to get the cache key for
  
  @return the cache key for the system id