private MetadataQueryService getMetadataQueryService() {
        if (metadataQueryService == null) {
            this.metadataQueryService = moduleManager.find(CoreModule.NAME)
                                                     .provider()
                                                     .getService(MetadataQueryService.class);
        }
        return metadataQueryService;
    }
@since 9.0.0 This query is replaced by {@link MetadataQueryV2}
oap-server/server-query-plugin/query-graphql-plugin/src/main/java/org/apache/skywalking/oap/query/graphql/resolver/MetadataQuery.java