docs: private void loadValuesInternal(List<Data> keys, boolean replaceExistingValues) throws Exception {
          if (!replaceExistingValues) {
              Future removeKeysFuture = removeExistingKeys(keys);
              removeKeysFuture.get();
          }
          removeUnloadableKeys(keys);
          if (keys.isEmpty()) {
              return;
          }
          List<Future> futures = doBatchLoad(keys);
          for (Future future : futures) {
              future.get();
          }
      }