@Test
public void testFilter() throws Exception {

    ServiceConfig serviceConfig = new ServiceConfig();
    serviceConfig.setFilter("mockfilter");
    assertThat(serviceConfig.getFilter(), equalTo("mockfilter"));
    Map<String, String> parameters = new HashMap<String, String>();
    parameters.put(Constants.SERVICE_FILTER_KEY, "prefilter");
    AbstractServiceConfig.appendParameters(parameters, serviceConfig);
    assertThat(parameters, hasEntry(Constants.SERVICE_FILTER_KEY, "prefilter,mockfilter"));
}