### Question:
YubicoClient { public static String getPublicId(String otp) { if ((otp == null) || (otp.length() < OTP_MIN_LEN)){ throw new IllegalArgumentException("The OTP is too short to be valid"); } Integer len = otp.length(); return otp.substring(0, len - 32).toLowerCase(); }  abstract VerificationResponse verify(String otp); Integer getClientId(); void setClientId(Integer clientId); void setKey(String key); String getKey(); void setSync(Integer sync); void setMaxRetries(int maxRetries); String[] getWsapiUrls(); void setWsapiUrls(String[] wsapi); void setUserAgent(String userAgent); static YubicoClient getClient(Integer clientId, String key); static String getPublicId(String otp); static boolean isValidOTPFormat(String otp);  }### Answer:
@Test public void testValidOTPPublicId() { String testOtp = "cccccccfhcbelrhifnjrrddcgrburluurftrgfdrdifj"; String testPublicId = "cccccccfhcbe"; String resultPublicId = YubicoClient.getPublicId(testOtp); assertEquals(testPublicId, resultPublicId); }
@Test(expected=IllegalArgumentException.class) public void testNullOTPPublicId() { YubicoClient.getPublicId(null); }
@Test(expected=IllegalArgumentException.class) public void testEmptyOTPPublicId() { YubicoClient.getPublicId(""); }