public byte[] data()
    {
        return sha1.digest();
    }
@Test
    public void testData()
    {
        byte[] buf = new byte[1024];
        Arrays.fill(buf, (byte) 0xAA);

        ZDigest digest = new ZDigest();

        digest.update(buf);
        byte[] data = digest.data();
        assertThat(byt(data[0]), is(0xDE));
        assertThat(byt(data[1]), is(0xB2));
        assertThat(byt(data[2]), is(0x38));
        assertThat(byt(data[3]), is(0x07));
    }