### Question:
JobUtil { public static int[] getPlaceHolder(String str, int start) { String scanString = str.substring(start); int index = scanString.indexOf(STARTER); if (index != INVALID_INDEX) { int endIndex = scanString.indexOf(CLOSER); if (endIndex != INVALID_INDEX) { return new int[] { start + index, start + endIndex }; } } return null; } private  JobUtil(); static String[] getPlaceHolders(String str); static int[] getPlaceHolder(String str, int start); static String replaceHolder(String str, String prop); static String getAndReplaceHolders(String str); static String replaceHolders(String str, String[] props); static String[] getAndReplaceHolders(String[] strArray); static boolean validateIPAddress(String address); static boolean validateFileSystemLocation(String address); static void enableProfiler(Job job, String params); static void disableProfiler(Job job); static void addClassPath(final Job job, String jars, String resources); static void addClassPath(final JobConf job, String jars,
			String resources); static void modifyOutputPath(Job job); static void modifyOutputPath(JobConf conf); static void modifyInputPath(Job job, String sampledDataPath); static void modifyInputPath(JobConf conf, String sampledDataPath);  }### Answer:
@Test public void testGetPlaceHolder() throws IOException { int[] value = JobUtil.getPlaceHolder(UtilitiesConstantsTestInterface.STR, 0); boolean check = value != null; assertTrue(check); }
@Test public void testGetPlaceHolderNull() throws IOException { int[] value = JobUtil.getPlaceHolder(UtilitiesConstantsTestInterface.STRING, 0); assertEquals(value, null); }