public String getStringArgument(String option) {
        return getStringArgument(option, null);
    }
@Test
    public void testGetStringArgument() throws ParseException {

        String[] args = {"--scan", "missing.file", "--artifactoryUsername", "blue42", "--project", "test"};

        CliParser instance = new CliParser(getSettings());
        try {
            instance.parse(args);
            Assert.fail("invalid scan argument should have caused an exception");
        } catch (FileNotFoundException ex) {
            Assert.assertTrue(ex.getMessage().contains("Invalid 'scan' argument"));
        }
        String expResult;
        String result = instance.getStringArgument("missingArgument");
        Assert.assertNull(result);

        expResult = "blue42";
        result = instance.getStringArgument(CliParser.ARGUMENT.ARTIFACTORY_USERNAME);
        Assert.assertEquals(expResult, result);
    }