@Override
    public Metrics toHour() {
        return null;
    }
Process have multiple labels, such as tag.
{@link ServiceLabelRecord} could combine them in the service level.
It could help to quickly locate the similar process by the service and label.
oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/manual/process/ServiceLabelRecord.java