objectIdToEntry.add(nullEntry = new Entry(newId(), null, 0));
objectIdToEntry.add(nullEntry = new Entry(newId(), null, Offset.zero()));
  public static void init() {    keyToEntry      = new Hashtable(5000);    objectIdToEntry = new ArrayList(5000);    // predefine "null" object    objectIdToEntry.add(nullEntry = new Entry(newId(), null, 0));    // slot 0 reserved for "null" object entry  }