public boolean contains(long value) {
        if (isEmpty()) {
            return false;
        }

        Sequence sequence = getHead();
        while (sequence != null) {
            if (sequence.contains(value)) {
                return true;
            }
            sequence = sequence.getNext();
        }

        return false;
    }
@Test
    public void testContains() {
        SequenceSet set = new SequenceSet();
        set.add(new Sequence(0, 10));
        set.add(new Sequence(21, 42));
        set.add(new Sequence(47, 90));
        set.add(new Sequence(142, 512));

        assertTrue(set.contains(0));
        assertTrue(set.contains(42));
        assertTrue(set.contains(49));
        assertTrue(set.contains(153));

        assertFalse(set.contains(43));
        assertFalse(set.contains(99));
        assertFalse(set.contains(-1));
        assertFalse(set.contains(11));
    }