public static Credentials create(ECKeyPair ecKeyPair) {
        String address = Numeric.prependHexPrefix(Keys.getAddress(ecKeyPair));
        return new Credentials(ecKeyPair, address);
    }
@Test
    public void testCredentialsFromECKeyPair() {
        Credentials credentials =
                Credentials.create(SampleKeys.PRIVATE_KEY_STRING, SampleKeys.PUBLIC_KEY_STRING);
        verify(credentials);
    }