### Question:
Util { public static String getStackTrace(Exception e) { StringWriter sw = new StringWriter(); e.printStackTrace(new PrintWriter(sw)); return sw.toString(); } private  Util(); static boolean contains(Map<String, ?> x, Map<String, ?> y, String[] keys); static String concatenate(Map<String, Object> map, String[] keys, String delimiter); static Map<String, Object> parseJson(String json); static String getUniqueID(String idstring); static String getStackTrace(Exception e); static String base64Decode(String encodedStr); static String encodeUrl(String toBeEncoded); static String base64Encode(String str); static Map<String,Object> getHeader(String base64Creds); static List<Map<String, T>> fetchDataFromS3(String s3Account,String s3Region,String s3Role, String bucketName,String path); static List<String> retrieveErrorRecords(String responseStr);  }### Answer:
@Test public void testGetStackTrace() { Assert.assertNotNull(Util.getStackTrace(new NullPointerException())); }