@Test
public void testSign() throws Exception {

    String signature = Crypto.sign("My message to sign", "my grain of salt".getBytes(Charsets.UTF_8.name()));
    assertThat(signature)
            .isNotNull()
            .isEqualTo("yIDXrtZ71qCfHnUNvlYSS//0YPE=")
            .isEqualTo(Crypto.sign("My message to sign", "my grain of salt".getBytes(Charsets.UTF_8.name())));
}