assertThat(server.getReceivedMessages().length, is(equalTo(NUMBER_OF_MESSAGES)));
flowExecutionListener.waitUntilFlowIsComplete();
Prober prober = new PollingProber(TIMEOUT_MILLIS, POLL_DELAY_MILLIS);
prober.check(new Probe()
{
@Override
public boolean isSatisfied()
{
return (retrievedMessages.size() == NUMBER_OF_MESSAGES);