    @Test
    public void testChild() throws NoSuchAlgorithmException, SignatureException, InvalidKeyException {

        String hxprv = "10fdbc41a4d3b8e5a0f50dd3905c1660e7476d4db3dbd9454fa4347500a633531c487e8174ffc0cfa76c3be6833111a9b8cd94446e37a76ee18bb21a7d6ea66b";
        String[] hpaths = {"010400000000000000", "0100000000000000"};
        byte[] childXprv = NonHardenedChild.child(Hex.decode(hxprv), hpaths);
        //expected: e8c0965af60563c4cabcf2e947b1cd955c4f501eb946ffc8c3447e5ec8a6335398a3720b3f96077fa187fdde48fe7dc293984b196f5e292ef8ed78fdbd8ed954
        //          e8c0965af60563c4cabcf2e947b1cd955c4f501eb946ffc8c3447e5ec8a6335398a3720b3f96077fa187fdde48fe7dc293984b196f5e292ef8ed78fdbd8ed954
    }