presto-main/src/main/java/io/prestosql/sql/analyzer/ExpressionAnalyzer.java/ExpressionAnalyzer/getLambdaArgumentReferences
class ExpressionAnalyzer:    public Map<NodeRef<Identifier>, LambdaArgumentDeclaration> getLambdaArgumentReferences()
    {
        return unmodifiableMap(lambdaArgumentReferences);
    }