presto-parser/src/main/java/io/prestosql/sql/ExpressionFormatter.java/Formatter/visitAtTimeZone
class Formatter:        @Override
        protected String visitAtTimeZone(AtTimeZone node, Void context)
        {
            return new StringBuilder()
                    .append(process(node.getValue(), context))
                    .append(" AT TIME ZONE ")
                    .append(process(node.getTimeZone(), context)).toString();
        }