docs: public static byte[] hmacSha1(final byte[] input, final byte[] key)
  		throws GeneralSecurityException {
  		try {
  			SecretKey secretKey = new SecretKeySpec(key, HMACSHA1_NAME);
  			Mac mac = Mac.getInstance(HMACSHA1_NAME);
  			mac.init(secretKey);
  			return mac.doFinal(input);
  		} catch (NoSuchAlgorithmException e) {
  			throw new ImpossibleException(e);
  		}
  	}