presto-main/src/main/java/io/prestosql/sql/planner/planprinter/PlanPrinter.java/Visitor/visitAssignUniqueId
class Visitor:        @Override
        public Void visitAssignUniqueId(AssignUniqueId node, Void context)
        {
            addNode(node, "AssignUniqueId");

            return processChildren(node, context);
        }