code: @Deprecated
      public double getRecentHitRate()
      {
          long r = requests.count();
          long h = hits.count();
          try
          {
              return ((double)(h - lastHits.get())) / (r - lastRequests.get());
          }
          finally
          {
              lastRequests.set(r);
              lastHits.set(h);
          }
      }
docs: for backward compatibility