public MatchResultImpl getPreviousResult() {
    if (previousResults.isEmpty()) {
      return null;
    }
    else {
      int index = previousResults.size() - 1;
      MatchResultImpl result = previousResults.get(index); // may contain nulls
      while (result == null && index > 0) {
        index--;
        result = previousResults.get(index);
      }
      return result;
    }
  }
public MatchResultImpl getPreviousResult()