I wonder if it would be possible to make the RectangleSpatialIndex class public. I am working on an alternative ObjectExtractor that finds rulings in a different manner, and it wants to make a Page the same way that ObjectExtractor does. However, it can't, because RectangleSpatialIndex is private.

Alternatively, if there were a way to invoke a different engine than ObjectExtractorStreamEngine from within ObjectExtractor, that'd work, too.