presto-parser/src/main/java/io/prestosql/sql/SqlFormatter.java/SqlFormatter/visitStartTransaction
class SqlFormatter:        @Override
        protected Void visitStartTransaction(StartTransaction node, Integer indent)
        {
            builder.append("START TRANSACTION");

            Iterator<TransactionMode> iterator = node.getTransactionModes().iterator();
            while (iterator.hasNext()) {
                builder.append(" ");
                process(iterator.next(), indent);
                if (iterator.hasNext()) {
                    builder.append(",");
                }
            }
            return null;
        }