code: @Override
      public CompletableFuture<Void> update(@NonNull Map<UUID, Long> values, @NonNull Duration timeout) {
          ensureInitialized();
          if (values.isEmpty()) {
              // Nothing to do.
              return CompletableFuture.completedFuture(null);
          }
  
          Collection<PageEntry> entries = values.entrySet().stream().map(this::serialize).collect(Collectors.toList());
          return executeConditionally(tm -> this.index.update(entries, tm), timeout);
      }
docs: region AttributeIndex Implementation