// make sure unreachable alts are as expected
if ( expectingUnreachableAlts!=null ) {
BitSet s = new BitSet();
s.addAll(expectingUnreachableAlts);
BitSet s2 = new BitSet();
s2.addAll(unreachableAlts);
assertEquals("unreachable alts mismatch", s, s2);
}
else {
assertEquals("number of unreachable alts", 0,
unreachableAlts!=null?unreachableAlts.size():0);