public static byte[] computeHmac(final byte[] key, final String string)
            throws SaslException {
        Mac mac = createSha1Hmac(key);
        mac.update(string.getBytes(StandardCharsets.UTF_8));
        return mac.doFinal();
    }
@Test
    public void testComputeHmac() throws Exception
    {
        // Setup test fixture.
        final byte[] key = StringUtils.decodeHex("1d96ee3a529b5a5f9e47c01f229a2cb8a6e15f7d"); // 'salted password' from the test vectors.
        final String value = "Client Key";

        // Execute system under test.
        final byte[] result = ScramUtils.computeHmac(key, value);

        // Verify results.
        assertArrayEquals(StringUtils.decodeHex("e234c47bf6c36696dd6d852b99aaa2ba26555728"), result); // test against 'client key' from the test vectors.
    }