presto-main/src/main/java/io/prestosql/operator/NestedLoopJoinOperator.java/NestedLoopJoinOperator/close
class NestedLoopJoinOperator:    @Override
    public void close()
    {
        buildPages = null;
        // We don't want to release the supplier multiple times, since its reference counted
        if (closed) {
            return;
        }
        closed = true;
        // `afterClose` must be run last.
        afterClose.run();
    }