presto-parser/src/main/java/io/prestosql/sql/tree/QuerySpecification.java/QuerySpecification/getChildren
class QuerySpecification:    @Override
    public List<Node> getChildren()
    {
        ImmutableList.Builder<Node> nodes = ImmutableList.builder();
        nodes.add(select);
        from.ifPresent(nodes::add);
        where.ifPresent(nodes::add);
        groupBy.ifPresent(nodes::add);
        having.ifPresent(nodes::add);
        orderBy.ifPresent(nodes::add);
        offset.ifPresent(nodes::add);
        limit.ifPresent(nodes::add);
        return nodes.build();
    }