private void verifyUnexpected() {
        if (!unexpected.isEmpty()) {
            final Notification firstUnexpected = this.unexpected.get(0);
            throw new IllegalStateException(String.format("Unexpected notifications received, count: [%d].  First" +
                            " notification is for id: [%d], deviceToken: [%s]", unexpected.size(),
                    firstUnexpected.getIdentifier(), Utilities.encodeHex(firstUnexpected.getDeviceToken())));
        }
    }
Provides a simulator that receives connection over TCP as per a real APNS server.  This class allows verification
and prior configuration of responses in a manner similar to a mocking framework.
src/test/java/com/notnoop/apns/utils/Simulator/ApnsSimulatorWithVerification.java