presto-parser/src/main/java/io/prestosql/sql/parser/AstBuilder.java/AstBuilder/visitQuantifiedComparison
class AstBuilder:    @Override
    public Node visitQuantifiedComparison(SqlBaseParser.QuantifiedComparisonContext context)
    {
        return new QuantifiedComparisonExpression(
                getLocation(context.comparisonOperator()),
                getComparisonOperator(((TerminalNode) context.comparisonOperator().getChild(0)).getSymbol()),
                getComparisonQuantifier(((TerminalNode) context.comparisonQuantifier().getChild(0)).getSymbol()),
                (Expression) visit(context.value),
                new SubqueryExpression(getLocation(context.query()), (Query) visit(context.query())));
    }