}

    @Override
    C someValue() {
        return toMutable(["s1", "s2"])
    }

    @Override
    C someOtherValue() {
        return toMutable(["s1"])
    }

    @Override
    C someOtherValue2() {
        return toMutable(["s2"])
    }

    @Override
    C someOtherValue3() {
        return toMutable(["s3"])
    }

    abstract AbstractCollectionProperty<String, C> property()

        return ['k1': 'v1', 'k2': 'v2']
    }

    @Override
    Map<String, String> someOtherValue() {
        return ['k1': 'v1']
    }

    @Override
    Map<String, String> someOtherValue2() {
        return ['k2': 'v2']
    }

    @Override
    Map<String, String> someOtherValue3() {
        return ['k3': 'v3']
    }

    @Override
    protected void setToNull(Object property) {