presto-main/src/main/java/io/prestosql/sql/planner/optimizations/PlanNodeDecorrelator.java/PlanNodeDecorrelator/containsCorrelation
class PlanNodeDecorrelator:    private boolean containsCorrelation(PlanNode node, List<Symbol> correlation)
    {
        return Sets.union(SymbolsExtractor.extractUnique(node, lookup), SymbolsExtractor.extractOutputSymbols(node, lookup)).stream().anyMatch(correlation::contains);
    }