### Question:
IRODSPasswordUtilities { public static String deriveHexSubsetOfChallenge(final String challengeValue) { if (challengeValue == null || challengeValue.isEmpty()) { throw new IllegalArgumentException("challengeValue is null or empty"); } byte[] temp = Base64.fromString(challengeValue); int subsetLength = 16; if (temp.length < subsetLength) { throw new IllegalArgumentException("challengeValue length is < 16"); } byte[] subsetBytes = Arrays.copyOfRange(temp, 0, 16); return getHexString(subsetBytes); }  static String obfuscateIRODSPasswordForAdminPasswordChange(final String newPassword,
			final String adminPassword, final String challengeValue); static String deriveHexSubsetOfChallenge(final String challengeValue); static String obfEncodeByKeyUsingPassword(final String sourceData, final String key, final boolean pad); static String obfEncodeByKey(final String sourceData, final String key, final boolean pad); static String obfuscateIRODSPasswordWithCypherChaining(final String newPassword, final String oldPassword); static String padPasswordWithRandomStringData(final String newPassword); static String getHexString(final byte[] b); static String getHexString2(final byte[] b); static int unsignedByteToInt(final byte b); static String getHashedPassword(final String passwordHashValue, final IRODSAccount irodsAccount); static String pad(String str, final int size, final char padChar); static final int WHEEL_LENGTH; static final int VAL_0; static final int VAL_A; static final int VAL_LC_A; static final int VAL_BANG; static final List<Integer> WHEEL; static final String RAND_STRING; static final String RAND_STRING_V2; static final int MAX_PWD_LENGTH; }### Answer:
@Test public void testDeriveHexSubsetOfChallenge() throws Exception { String challenge = "uejIyZS2C5h33yMdZsN8bptECJnymAhUmdqsA40/LkMfztiLjrILv+c3xJK9SVJXX7KKAX84Y9c8FtSwuMbR2A=="; String expected = "b9e8c8c994b60b9877df231d66c37c6e"; String actual = IRODSPasswordUtilities.deriveHexSubsetOfChallenge(challenge); Assert.assertEquals("did not correctly derive challenge value", expected, actual); }