private DirectionalLightShadowFilter createDirectionalLightShadowFilter(AssetManager assetManager) {
        DirectionalLight light = new DirectionalLight();
        light.setDirection(new Vector3f(-1, -2, -3).normalizeLocal());
        light.setColor(new ColorRGBA(0.8f, 0.8f, 0.8f, 1f));

        DirectionalLightShadowFilter dlsf = new DirectionalLightShadowFilter(assetManager, 2048, 1);
        dlsf.setLight(light);

        return dlsf;
    }
Tests serialization and de-serialization of a {@code FilterPostProcessing}.
jme3-core/src/test/java/com/jme3/shadow/FilterPostProcessingTest.java