@Test
public void getNext() {

	final int MAX_ITERATIONS = 100000;
	final Sequence sequence = new Sequence();
	Thread th_1 = new Thread(() -> {
		for (int k = 0; k < MAX_ITERATIONS; k++)
			sequence.getNext();
	});
	Thread th_2 = new Thread(() -> {
		for (int k = 0; k < MAX_ITERATIONS; k++)
			sequence.getNext();
	});
	th_1.start();
	th_2.start();
	try {
		th_1.join();
		th_2.join();
	}
	catch (InterruptedException e) {
		e.printStackTrace();
	}
	assertEquals(MAX_ITERATIONS * 2, sequence.getValue());
}