    @Test
    public void cli_testOption_shouldPrintHelp(){

        String[] args=new String[]{"-help"};
        CliLtrTools.main(args);
        final String expectedHelpMessage = "usage: ltr-tools\n" +
            " -categoricalFeatures <file>   use given list of categorical features\n" +
            " -features <file>              use given mapping file to resolve the\n" +
            "                               feature ids to the feature name\n" +
            " -help                         print this message\n" +
            " -model <file>                 use given model\n" +
            " -solrURL <URL>                use given solr base URL\n" +
            " -tool <name>                  run the selected tool :\n" +
            "                               [modelIndexer,trainingSetIndexer,topScoring\n" +
            "                               LeavesViewer]\n" +
            " -topK <int>                   print the top scoring leaves up to the\n" +
            "                               value given\n" +
            " -trainingSet <file>           use given training set file, the format\n" +
            "                               supported is the RankLib one\n";
        assertThat(outContent.toString(),is(expectedHelpMessage));
    }