code: public List<String> getPathsForBuckets(CmsFlexRequestKey key) {
  
          PathsBean pathBean = key.getPaths();
          List<String> paths = Lists.newArrayList();
          if (m_uri != null) {
              paths.add(pathBean.getUri());
              paths.add(pathBean.getDetailElement());
          }
          if (m_site != null) {
              paths.add(pathBean.getSite());
          }
          if (m_containerElement != null) {
              paths.add(pathBean.getContainerElement());
          }
  
          paths.removeAll(Collections.singletonList(null));
          return paths;
      }
docs: Gets the list of root paths for the cache key / request key combination which should be used to determine the set of flex cache buckets for the flex cache entry.<p>
  
  @param key the flex request key
  @return the list of paths which should be used to determine the flex cache buckets