presto-main/src/main/java/io/prestosql/sql/planner/planprinter/PlanPrinter.java/Visitor/printDynamicFilterAssignments
class Visitor:        private String printDynamicFilterAssignments(Map<String, Symbol> filters)
        {
            return filters.entrySet().stream()
                    .map(filter -> filter.getValue() + " -> " + filter.getKey())
                    .collect(Collectors.joining(", ", "{", "}"));
        }