presto-main/src/main/java/io/prestosql/sql/planner/plan/SimplePlanRewriter.java/SimplePlanRewriter/defaultRewrite
class SimplePlanRewriter:        public PlanNode defaultRewrite(PlanNode node, C context)
        {
            List<PlanNode> children = node.getSources().stream()
                    .map(child -> rewrite(child, context))
                    .collect(toImmutableList());

            return replaceChildren(node, children);
        }