code: @Override
      public CacheManager.CacheStatus getCacheStatus() {
          int minGen = 0;
          int maxGen = 0;
          long size = 0;
          synchronized (this.segmentCaches) {
              for (SegmentKeyCache e : this.segmentCaches.values()) {
                  if (e != null) {
                      val cs = e.getCacheStatus();
                      minGen = Math.min(minGen, cs.getOldestGeneration());
                      maxGen = Math.max(maxGen, cs.getNewestGeneration());
                      size += cs.getSize();
                  }
              }
          }
  
          return new CacheManager.CacheStatus(size, minGen, maxGen);
      }
docs: region CacheManager.Client Implementation