}

    @Test
    void testSequenceNumbers() {
        long seq1 = registration.getNextSequenceNumber();
        long seq2 = registration.getNextSequenceNumber();
        long seq3 = registration.getNextSequenceNumber();

        assertEquals(1, seq1);
        assertEquals(2, seq2);
        assertEquals(3, seq3);
        assertTrue(seq2 > seq1);

    }

    /**
     * Gets the next sequence number for this registration.
     *
     * @return the next sequence number
     */
    public long getNextSequenceNumber() {
        return sequenceNumber.incrementAndGet();
    }

    /**
     * Updates the heartbeat timestamp to current time and resets failure count.
     */
    public void updateHeartbeat() {

    assertFalse(registration.isExpired(60000));
    
    // Test sequence numbers
    long seq1 = registration.getNextSequenceNumber();
    long seq2 = registration.getNextSequenceNumber();
    assertEquals(seq1 + 1, seq2);
}

@Test
public void testWitnessNotification() {
    WitnessNotification notification = new WitnessNotification(

        try {
            WitnessHeartbeatRequest request = new WitnessHeartbeatRequest();
            request.setRegistrationId(registration.getRegistrationId());
            request.setSequenceNumber(registration.getNextSequenceNumber());

            WitnessHeartbeatResponse response = rpcClient.heartbeat(request);

            if (response != null && response.isSuccess()) {
                registration.updateHeartbeat();