@Override
  public boolean removeFailedPathInfo(PcePathInfo failedPathInfo) {
    checkNotNull(failedPathInfo, PATH_INFO_NULL);

    if (!failedPathSet.remove(failedPathInfo)) {
      log.error("Failed path info {} deletion has failed.", failedPathInfo.toString());
      return false;
    }
    return true;
  }
 @Override
 public int getFailedPathInfoCount() {
   return failedPathSet.size();
 }
 @Override
 public void addFailedPathInfo(PcePathInfo failedPathInfo) {
   checkNotNull(failedPathInfo, PATH_INFO_NULL);
   failedPathSet.add(failedPathInfo);
 }
 @Override
 public boolean existsFailedPathInfo(PcePathInfo failedPathInfo) {
   checkNotNull(failedPathInfo, PATH_INFO_NULL);
   return failedPathSet.contains(failedPathInfo);
 }