### Question:
AbstractServiceConfig extends AbstractInterfaceConfig { @Override @Parameter(key = Constants.SERVICE_FILTER_KEY, append = true) public String getFilter() { return super.getFilter(); }  String getVersion(); void setVersion(String version); String getGroup(); void setGroup(String group); Integer getDelay(); void setDelay(Integer delay); Boolean getExport(); void setExport(Boolean export); Integer getWeight(); void setWeight(Integer weight); @Parameter(escaped = true) String getDocument(); void setDocument(String document); String getToken(); void setToken(String token); void setToken(Boolean token); Boolean isDeprecated(); void setDeprecated(Boolean deprecated); Boolean isDynamic(); void setDynamic(Boolean dynamic); List<ProtocolConfig> getProtocols(); @SuppressWarnings({"unchecked"}) void setProtocols(List<? extends ProtocolConfig> protocols); ProtocolConfig getProtocol(); void setProtocol(ProtocolConfig protocol); String getAccesslog(); void setAccesslog(String accesslog); void setAccesslog(Boolean accesslog); Integer getExecutes(); void setExecutes(Integer executes); @Override @Parameter(key = Constants.SERVICE_FILTER_KEY, append = true) String getFilter(); @Override @Parameter(key = Constants.EXPORTER_LISTENER_KEY, append = true) String getListener(); @Override void setListener(String listener); Boolean isRegister(); void setRegister(Boolean register); Integer getWarmup(); void setWarmup(Integer warmup); String getSerialization(); void setSerialization(String serialization);  }### Answer:
@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")); }