@Override
 public BitSet findMatchings(
     T expectedElement, List<T> annotatorResult, BitSet alreadyUsedResults) {
   BitSet matchings;
   matchings =
       matchingsCounter[0].findMatchings(expectedElement, annotatorResult, alreadyUsedResults);
   for (int i = 1; (i < matchingsCounter.length) && (!matchings.isEmpty()); i++) {
     matchings.intersect(
         matchingsCounter[i].findMatchings(expectedElement, annotatorResult, alreadyUsedResults));
   }
   return matchings;
 }
 @Override
 public boolean isEmpty() {
   return bitSet.isEmpty();
 }