### Question:
ConfigAccessor { public void setRESTConfig(String clusterName, RESTConfig restConfig) { updateRESTConfig(clusterName, restConfig, true); } private  ConfigAccessor(RealmAwareZkClient zkClient, boolean usesExternalZkClient); @Deprecated  ConfigAccessor(RealmAwareZkClient zkClient); @Deprecated  ConfigAccessor(String zkAddress); @Deprecated String get(ConfigScope scope, String key); @Deprecated Map<String, String> get(ConfigScope scope, List<String> keys); String get(HelixConfigScope scope, String key); Map<String, String> get(HelixConfigScope scope, List<String> keys); @Deprecated void set(ConfigScope scope, String key, String value); @Deprecated void set(ConfigScope scope, Map<String, String> keyValueMap); void set(HelixConfigScope scope, String key, String value); void set(HelixConfigScope scope, Map<String, String> keyValueMap); @Deprecated void remove(ConfigScope scope, String key); @Deprecated void remove(ConfigScope scope, List<String> keys); void remove(HelixConfigScope scope, String key); void remove(HelixConfigScope scope, List<String> keys); void remove(HelixConfigScope scope, ZNRecord recordToRemove); @Deprecated List<String> getKeys(ConfigScopeProperty type, String clusterName, String... keys); List<String> getKeys(HelixConfigScope scope); CustomizedStateConfig getCustomizedStateConfig(String clusterName); ClusterConfig getClusterConfig(String clusterName); CloudConfig getCloudConfig(String clusterName); void deleteCloudConfigFields(String clusterName, CloudConfig cloudConfig); void updateCloudConfig(String clusterName, CloudConfig cloudConfig); RESTConfig getRESTConfig(String clusterName); void setRESTConfig(String clusterName, RESTConfig restConfig); void updateRESTConfig(String clusterName, RESTConfig restConfig); void deleteRESTConfig(String clusterName); void setClusterConfig(String clusterName, ClusterConfig clusterConfig); void updateClusterConfig(String clusterName, ClusterConfig clusterConfig); ResourceConfig getResourceConfig(String clusterName, String resourceName); void setResourceConfig(String clusterName, String resourceName,
      ResourceConfig resourceConfig); void updateResourceConfig(String clusterName, String resourceName,
      ResourceConfig resourceConfig); InstanceConfig getInstanceConfig(String clusterName, String instanceName); void setInstanceConfig(String clusterName, String instanceName,
      InstanceConfig instanceConfig); void updateInstanceConfig(String clusterName, String instanceName,
      InstanceConfig instanceConfig); void close(); @Override void finalize();  }### Answer:
@Test public void testSetRestConfig() { String className = TestHelper.getTestClassName(); String methodName = TestHelper.getTestMethodName(); String clusterName = className + "_" + methodName; ZKHelixAdmin admin = new ZKHelixAdmin(ZK_ADDR); admin.addCluster(clusterName, true); ConfigAccessor configAccessor = new ConfigAccessor(ZK_ADDR); HelixConfigScope scope = new HelixConfigScopeBuilder(ConfigScopeProperty.REST).forCluster(clusterName).build(); Assert.assertNull(configAccessor.getRESTConfig(clusterName)); RESTConfig restConfig = new RESTConfig(clusterName); restConfig.set(RESTConfig.SimpleFields.CUSTOMIZED_HEALTH_URL, "TEST_URL"); configAccessor.setRESTConfig(clusterName, restConfig); Assert.assertEquals(restConfig, configAccessor.getRESTConfig(clusterName)); }