### Question:
HMAC { public static byte[] initMacKey() { try { KeyGenerator keyGenerator = KeyGenerator.getInstance(ISecurity.HMAC_ALGORITHM); SecretKey secretKey = keyGenerator.generateKey(); return secretKey.getEncoded(); } catch (NoSuchAlgorithmException e) { throw new RuntimeException("获取自增密钥错误", e); } }  static byte[] encrypt(byte[] data, byte[] key); static byte[] initMacKey();  }### Answer:
@Test public void testInitMacKey() { assertNotNull(HMAC.initMacKey()); }