### Question:
CryptoServiceSingleton implements Crypto { @Override public String generateToken() { byte[] bytes = new byte[12]; random.nextBytes(bytes); return hexToString(bytes); } @SuppressWarnings("UnusedDeclaration")  CryptoServiceSingleton(@Requires ApplicationConfiguration configuration);  CryptoServiceSingleton(String secret, Hash defaultHash,
                                  Integer keySize, String transformation, Integer iterationCount); @Override String encryptAESWithCBC(String value, String salt); @Override String encryptAESWithCBC(String value, String privateKey, String salt, String iv); @Override String decryptAESWithCBC(String value, String salt); @Override String decryptAESWithCBC(String value, String privateKey, String salt, String iv); @Override String sign(String message); @Override String sign(String message, byte[] key); @Override String hash(String input); @Override String hash(String input, Hash hashType); @Override String encryptAES(String value); @Override String encryptAES(String value, String privateKey); @Override String decryptAES(String value); @Override String decryptAES(String value, String privateKey); @Override String signToken(String token); @Override String extractSignedToken(String token); boolean constantTimeEquals(String a, String b); @Override String encodeBase64(byte[] value); @Override byte[] decodeBase64(String value); @Override String hexMD5(String value); @Override String hexSHA1(String value); @Override String generateToken(); @Override String generateSignedToken(); @Override boolean compareSignedTokens(String tokenA, String tokenB); @Override byte[] md5(String toHash); @Override byte[] sha1(String toHash); @Override char[] hex(byte[] bytes); @Override String hexToString(byte[] bytes); @Override byte[] decodeHex(String value); static final String AES_ECB_ALGORITHM; static final String HMAC_SHA_1; static final String PBKDF_2_WITH_HMAC_SHA_1; }### Answer:
@Test public void testTokenGeneration() { String token = crypto.generateToken(); assertThat(token).isNotNull().isNotEmpty(); String token2 = crypto.generateToken(); assertThat(token2).isNotNull().isNotEmpty(); assertThat(token).isNotEqualTo(token2); }