code: func ClusterGeoClusters(clusters []*Cluster, threshold float64) []*Cluster {
  	if len(clusters) < 2 {
  		return clusters
  	}
  
  	copiedClusters := make([]*Cluster, len(clusters), len(clusters))
  	for i, cluster := range clusters {
  		copiedClusters[i] = NewClusterWithCentroid(cluster.Centroid, cluster.Pointers...)
  	}
  
  	return geocluster(copiedClusters, threshold)
  }
docs: // ClusterGeoClusters can be used if you've already created clusters objects
  // using a prefilterer of something else.