private void readObject(java.io.ObjectInputStream s) throws IOException, ClassNotFoundException {
    s.defaultReadObject();      // Read nothing
    initialize(MIN_SIZE);
    for(;;) {
      final TypeK K = (TypeK) s.readObject();
      final TypeV V = (TypeV) s.readObject();
      if( K == null ) break;
      put(K,V);                 // Insert with an offical put
    }
  }