public CompletableFuture<MetricsType> typeOfMetrics(String name) {
        return queryAsync(() -> MetricsMetadataQueryService.typeOfMetrics(name));
    }
Metrics definition metadata query. Response the metrics type which determines the suitable query methods.
oap-server/server-query-plugin/query-graphql-plugin/src/main/java/org/apache/skywalking/oap/query/graphql/resolver/MetricsQuery.java