Set<Feature<?>> inverseFeatures = new HashSet<>(mapFeatures);

    boolean nullKeys = inverseFeatures.remove(MapFeature.ALLOWS_NULL_KEYS);
    boolean nullValues = inverseFeatures.remove(MapFeature.ALLOWS_NULL_VALUES);

    if (nullKeys) {
      inverseFeatures.add(MapFeature.ALLOWS_NULL_VALUES);
    }
    if (nullValues) {

    }

    /**
     * Test Rule with null ResponseData
     */
    public void test_matchWithNullResponseData() {
        ConfigurableRule rule = new ConfigurableRule();
        rule.setRuleId("nullTest");
        rule.setResponseProcessor(new TestResponseProcessor("nullProcessor"));

        // Should handle null gracefully
        assertFalse(rule.match(null));
    }

    /**

// https://www.iana.org/domains/root/db/sony.html
sony

// soy : Charleston Road Registry Inc.
// https://www.iana.org/domains/root/db/soy.html
soy

// spa : Asia Spa and Wellness Promotion Council Limited
// https://www.iana.org/domains/root/db/spa.html
spa

// space : Radix Technologies Inc.
// https://www.iana.org/domains/root/db/space.html
space