if ( alts!=null ) {
buf.append("\\n");
// separate alts
IntegerList altList = new IntegerList();
altList.addAll(alts);
altList.sort();
Set<ATNConfig> configurations = s.configs;
for (int altIndex = 0; altIndex < altList.size(); altIndex++) {
int alt = altList.get(altIndex);
if ( altIndex>0 ) {
buf.append("\\n");