@VisibleForTesting
 public ReaderState state(SSTableReader reader) {
   SSTableReader currentlyVisible =
       ReaderState.visible(reader, in(logged.obsolete), logged.update, originals);
   SSTableReader nextVisible =
       ReaderState.visible(
           reader,
           orIn(staged.obsolete, logged.obsolete),
           staged.update,
           logged.update,
           originals);
   return new ReaderState(
       ReaderState.Action.get(logged.update.contains(reader), logged.obsolete.contains(reader)),
       ReaderState.Action.get(staged.update.contains(reader), staged.obsolete.contains(reader)),
       currentlyVisible,
       nextVisible,
       originals.contains(reader));
 }