public static String substVars(String val, PropertyContainer pc1) throws ScanException {
        return substVars(val, pc1, null);
    }
@Test
    public void testSubstVarsWithDefault() throws ScanException {
        context.putProperty("v1", "if");
        String textWithDefault = "Testing ${v1} variable substitution ${v2:-toto}";
        String resultWithDefault = "Testing if variable substitution toto";

        String result = OptionHelper.substVars(textWithDefault, context);
        assertEquals(resultWithDefault, result);
    }