Remove one unused method. (#12840)

Author: wu-sheng

oap-server/server-storage-plugin/storage-elasticsearch-plugin/src/main/java/org/apache/skywalking/oap/server/storage/plugin/elasticsearch/query/MetadataQueryEsDAO.java

@@ -22,6 +22,11 @@
 import com.google.gson.Gson;
 import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.function.Function;
+import java.util.stream.Collectors;
 import javax.annotation.Nullable;
 import org.apache.commons.lang3.StringUtils;
 import org.apache.skywalking.library.elasticsearch.requests.search.BoolQueryBuilder;
@@ -58,12 +63,6 @@
 import org.apache.skywalking.oap.server.storage.plugin.elasticsearch.base.IndexController;
 import org.apache.skywalking.oap.server.storage.plugin.elasticsearch.base.MatchCNameBuilder;
 
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Map;
-import java.util.function.Function;
-import java.util.stream.Collectors;
-
 import static org.apache.skywalking.oap.server.core.analysis.manual.instance.InstanceTraffic.PropertyUtil.LANGUAGE;
 
 public class MetadataQueryEsDAO extends EsDAO implements IMetadataQueryDAO {
@@ -418,14 +417,6 @@ public Process getProcess(String processId) {
         return null;
     }
 
-    private List<Service> buildServices(SearchResponse response) {
-        List<Service> services = new ArrayList<>();
-        for (SearchHit hit : response.getHits()) {
-            services.add(searchHitServiceFunction.apply(hit));
-        }
-        return services;
-    }
-
     private List<ServiceInstance> buildInstances(SearchResponse response) {
         List<ServiceInstance> serviceInstances = new ArrayList<>();
         for (SearchHit searchHit : response.getHits()) {