private void purge(){
synchronized (queue) {
    WeakKey key;
    while ((key=(WeakKey)queue.poll()) != null) {
      super.remove(key.getReferenced());
    }
  }
}

private void purge ( ) { synchronized ( queue ) { WeakKey key ; while ( ( key = ( WeakKey ) queue . poll ( ) ) != null ) { super . remove ( key . getReferenced ( ) ) ; } } }
purges all entries whose wrapped keys have been garbage collected .
