d, err := newWarmBackend(ctx, tier, true)
	if err != nil {
		return err
	}

	if !ignoreInUse {
		// Check if warmbackend is in use by other MinIO tenants
		inUse, err := d.InUse(ctx)
		if err != nil {
			return err
		}
		if inUse {
			return errTierBackendInUse
		}
	}

	config.Tiers[tierName] = tier
	config.drivercache[tierName] = d

	return nil
}

                if ( st == 2 ) {
                    long l = this.usageCount.get();
                    if ( ( inUse && l != 1 ) || ( !inUse && l > 0 ) ) {
                        log.warn("Disconnected tree while still in use " + this);
                        dumpResource();
                        wasInUse = true;
                        if ( sess.getConfig().isTraceResourceUsage() ) {

          "step": 2
        },
        {
          "datasource": {
            "type": "prometheus",
            "uid": "${datasource}"
          },
          "expr": "go_memstats_heap_inuse_bytes{app=\"istiod\"}",
          "format": "time_series",
          "hide": false,
          "intervalFactor": 2,
          "legendFormat": "Heap in-use",
          "refId": "E",
          "step": 2