public MapConfig setMergePolicyConfig(MergePolicyConfig mergePolicyConfig) {
        this.mergePolicyConfig = checkNotNull(mergePolicyConfig,
                "mergePolicyConfig cannot be null!");
        return this;
    }
@Test
    public void testSetMergePolicyConfig() {
        MergePolicyConfig mergePolicyConfig = new MergePolicyConfig()
                .setPolicy(PassThroughMergePolicy.class.getName())
                .setBatchSize(2342);

        MapConfig config = new MapConfig();
        config.setMergePolicyConfig(mergePolicyConfig);

        assertEquals(PassThroughMergePolicy.class.getName(), config.getMergePolicyConfig().getPolicy());
        assertEquals(2342, config.getMergePolicyConfig().getBatchSize());
    }