return c.filterClusters(func(cc Cluster) bool {
		return !cc.IsExternalControlPlane()
	}, exclude(excluded...))
}

// IsExternalControlPlane indicates whether the clusters are set up in an enternal
// control plane configuration. An external control plane is a primary cluster that
// gets its Istio configuration from a different cluster.
func (c Clusters) IsExternalControlPlane() bool {
	for _, cc := range c {