GetConnThread gct = new GetConnThread(mgr, route, 0L); // no timeout
gct.start();
Thread.sleep(100); // give extra thread time to block
mgr.shutdown();
// First release the connection. If the manager keeps working
// despite the shutdown, this will deblock the extra thread.
// The release itself should turn into a no-op, without exception.
mgr.releaseConnection(conn, -1, null);