void checkConsistency() {
    rwLock.readLock().lock();
    try {
      IntIterator keyIt1 = singularMapping.keySet().intIterator();
      while (keyIt1.hasNext()) {
        checkConsistency(keyIt1.nextInt());
      }
      IntIterator keyIt2 = multiMapping.keySet().intIterator();
      while (keyIt2.hasNext()) {
        checkConsistency(keyIt2.nextInt());
      }
    }
    finally {
      rwLock.readLock().unlock();
    }
  }
void checkConsistency()