presto-parser/src/main/java/io/prestosql/sql/parser/AstBuilder.java/AstBuilder/visitSubqueryExpression
class AstBuilder:    @Override
    public Node visitSubqueryExpression(SqlBaseParser.SubqueryExpressionContext context)
    {
        return new SubqueryExpression(getLocation(context), (Query) visit(context.query()));
    }