@Override
    public void activateMetricsShard(CoordinatorMetricsShard shard) {
        if (!(shard instanceof GroupCoordinatorMetricsShard)) {
            throw new IllegalArgumentException("GroupCoordinatorMetrics can only activate GroupCoordinatorMetricShard");
        }
        shards.put(shard.topicPartition(), (GroupCoordinatorMetricsShard) shard);
    }
Global sensors. These are shared across all metrics shards.
group-coordinator/src/main/java/org/apache/kafka/coordinator/group/metrics/GroupCoordinatorMetrics.java