private static final String STATUS = "status";
    private static final String TIMED_OUT = "timed_out";
    private static final String NUMBER_OF_NODES = "number_of_nodes";
    private static final String NUMBER_OF_DATA_NODES = "number_of_data_nodes";
    private static final String NUMBER_OF_PENDING_TASKS = "number_of_pending_tasks";
    private static final String NUMBER_OF_IN_FLIGHT_FETCH = "number_of_in_flight_fetch";

        assertTrue(mockConfig.getApiPingEsFieldSet().contains("timed_out"));
        assertTrue(mockConfig.getApiPingEsFieldSet().contains("number_of_nodes"));
        assertTrue(mockConfig.getApiPingEsFieldSet().contains("number_of_data_nodes"));
        assertTrue(mockConfig.getApiPingEsFieldSet().contains("active_primary_shards"));
        assertTrue(mockConfig.getApiPingEsFieldSet().contains("active_shards"));

        private static final long serialVersionUID = 1L;

        @Override
        public String getApiPingSearchEngineFields() {
            return "cluster_name,status,timed_out,number_of_nodes,number_of_data_nodes,active_primary_shards,active_shards,relocating_shards,initializing_shards,unassigned_shards,delayed_unassigned_shards,number_of_pending_tasks,number_of_in_flight_fetch,task_max_waiting_in_queue_millis,active_shards_percent_as_number";