static KeyPair createSecp256k1KeyPair()
            throws NoSuchProviderException,
                    NoSuchAlgorithmException,
                    InvalidAlgorithmParameterException {
        return createSecp256k1KeyPair(secureRandom());
    }
@Test
    public void testCreateSecp256k1KeyPair() throws Exception {
        KeyPair keyPair = Keys.createSecp256k1KeyPair();
        PrivateKey privateKey = keyPair.getPrivate();
        PublicKey publicKey = keyPair.getPublic();

        assertNotNull(privateKey);
        assertNotNull(publicKey);

        assertEquals(privateKey.getEncoded().length, (144));
        assertEquals(publicKey.getEncoded().length, (88));
    }