public boolean contains(int value) {
        return contains(Util.toUnsignedLong(value));
    }
@Test
    public void testContains() {
        // empty
        Assert.assertFalse(emptyBitmap.contains(1));

        // single value
        Assert.assertTrue(singleBitmap.contains(1));
        Assert.assertFalse(singleBitmap.contains(2));

        // bitmap
        Assert.assertTrue(largeBitmap.contains(1));
        Assert.assertFalse(largeBitmap.contains(100));

        // set
        Assert.assertTrue(mediumBitmap.contains(1));
        Assert.assertFalse(mediumBitmap.contains(20));
    }