public RegistryBuilder appendParameter(String key, String value) {
        this.parameters = appendParameter(parameters, key, value);
        return getThis();
    }
@Test
    void appendParameter() {
        RegistryBuilder builder = new RegistryBuilder();
        builder.appendParameter("default.num", "one").appendParameter("num", "ONE");

        Map<String, String> parameters = builder.build().getParameters();

        Assertions.assertTrue(parameters.containsKey("default.num"));
        Assertions.assertEquals("ONE", parameters.get("num"));
    }