@Test
public void testSignMessage() {

    Sign.SignatureData signatureData = Sign.signMessage(TEST_MESSAGE, SampleKeys.KEY_PAIR);
    Sign.SignatureData expected = new Sign.SignatureData(
            (byte) 27,
            Numeric.hexStringToByteArray(
                    "0x9631f6d21dec448a213585a4a41a28ef3d4337548aa34734478b563036163786"),
            Numeric.hexStringToByteArray(
                    "0x2ff816ee6bbb82719e983ecd8a33a4b45d32a4b58377ef1381163d75eedc900b")
    );
    assertThat(signatureData, is(expected));
}