public final long toLong(byte[] b) {
        return toLong(b, 0);
    }
@Test
    public void testToLong() {
        byte[] bytes = bitUtil.fromLong(Long.MAX_VALUE);
        assertEquals(Long.MAX_VALUE, bitUtil.toLong(bytes));

        bytes = bitUtil.fromLong(Long.MAX_VALUE / 7);
        assertEquals(Long.MAX_VALUE / 7, bitUtil.toLong(bytes));
    }