@Test
public void testDoubleConnectionAcquire() {

  ConnectionQueue queue = new ConnectionQueue();
  ConnectionPool pool = new ConnectionPool(queue, 1);
  SimpleHolder holder = new SimpleHolder();
  pool.acquire(holder);
  SimpleConnection conn = new SimpleConnection();
  queue.connect(conn);
  holder.init();
  try {
    holder.init();
    fail();
  } catch (IllegalStateException ignore) {
  }
}