MissingRequiredParams error shows optional indexed Parameters

[remkop]

    @Test
    public void testMissingRequiredParams() {
        class Example {
            @Parameters(index = "1", arity = "0..1") String optional;
            @Parameters(index = "0") String mandatory;
        }
        try { CommandLine.parse(new Example(), new String[] {"mandatory"}); }
        catch(MissingParameterException ex) { fail(); }

        try {
            CommandLine.parse(new Example(), new String[0]);
            fail("Should not accept missing mandatory parameter");
        } catch(MissingParameterException ex) {
            assertEquals("Missing required parameter: mandatory", ex.getMessage());
        }
    }
    @Test
    public void testMissingRequiredParams1() {
        class Tricky1 {
            @Parameters(index = "2") String anotherMandatory;
            @Parameters(index = "1", arity = "0..1") String optional;
            @Parameters(index = "0") String mandatory;
        }
        try {
            CommandLine.parse(new Tricky1(), new String[0]);
            fail("Should not accept missing mandatory parameter");
        } catch(MissingParameterException ex) {
            assertEquals("Missing required parameters: mandatory, anotherMandatory", ex.getMessage());
        }
        try {
            CommandLine.parse(new Tricky1(), new String[] {"firstonly"});
            fail("Should not accept missing mandatory parameter");
        } catch(MissingParameterException ex) {
            assertEquals("Missing required parameter: anotherMandatory", ex.getMessage());
        }
    }
    @Test
    public void testMissingRequiredParams2() {
        class Tricky2 {
            @Parameters(index = "2", arity = "0..1") String anotherOptional;
            @Parameters(index = "1", arity = "0..1") String optional;
            @Parameters(index = "0") String mandatory;
        }
        try { CommandLine.parse(new Tricky2(), new String[] {"mandatory"}); }
        catch(MissingParameterException ex) { fail(); }

        try {
            CommandLine.parse(new Tricky2(), new String[0]);
            fail("Should not accept missing mandatory parameter");
        } catch(MissingParameterException ex) {
            assertEquals("Missing required parameter: mandatory", ex.getMessage());
        }
    }

[remkop]

assertNoMissingParameters method

                if (arity == 1) {
                    if (field.isAnnotationPresent(Option.class)) {
                        throw new MissingParameterException("Missing required parameter for " +
                                optionDescription("", field, 0));
                    }
                    Arity indexRange = Arity.valueOf(field.getAnnotation(Parameters.class).index());
                    Help.IParamLabelRenderer labelRenderer = Help.createMinimalParamLabelRenderer();
                    String sep = "";
                    String names = "";
                    int count = 0;
                    for (int i = indexRange.min; i < positionalParametersFields.size(); i++) {
                        if (Arity.forParameters(positionalParametersFields.get(i)).min > 0) {
                            names += sep + labelRenderer.renderParameterLabel(positionalParametersFields.get(i),
                                    Collections.<IStyle>emptyList());
                            sep = ", ";
                            count++;
                        }
                    }
                    String msg = "Missing required parameter";
                    Arity paramArity = Arity.forParameters(field);
                    if (paramArity.isVariable) {
                        msg += "s at positions " + paramArity + ": ";
                    } else {
                        msg += (count > 1 ? "s: " : ": ");
                    }
                    throw new MissingParameterException(msg + names);
                }