public void destroy(){
  lock.lock();
  try {
    if (isOpen()) {
      close();
    }
    deleteResources();
  }
  finally {
    lock.unlock();
  }
}

public void destroy ( ) { lock . lock ( ) ; try { if ( isOpen ( ) ) { close ( ) ; } deleteResources ( ) ; } finally { lock . unlock ( ) ; } }
atomically closes the store ( iff open ) and then deletes the backing file .
