presto-main/src/main/java/io/prestosql/operator/SpatialJoinOperator.java/SpatialJoinOperator/close
class SpatialJoinOperator:    @Override
    public void close()
    {
        if (closed) {
            return;
        }
        closed = true;

        pagesSpatialIndexFuture = null;
        onClose.run();
    }