presto-main/src/main/java/io/prestosql/sql/planner/SubqueryPlanner.java/SubqueryPlanner/visitUnnest
class SubqueryPlanner:        @Override
        public PlanNode visitUnnest(UnnestNode node, RewriteContext<Void> context)
        {
            UnnestNode rewrittenNode = (UnnestNode) context.defaultRewrite(node);
            return new UnnestNode(
                    node.getId(),
                    rewrittenNode.getSource(),
                    rewrittenNode.getReplicateSymbols(),
                    rewrittenNode.getUnnestSymbols(),
                    rewrittenNode.getOrdinalitySymbol(),
                    rewrittenNode.getJoinType(),
                    rewrittenNode.getFilter().map(expression -> replaceExpression(expression, mapping)));
        }