code: func BootstrapWithSingleStore(cluster *Cluster) (storeID, peerID, regionID uint64) {
  	ids := cluster.AllocIDs(3)
  	storeID, peerID, regionID = ids[0], ids[1], ids[2]
  	cluster.AddStore(storeID, fmt.Sprintf("store%d", storeID))
  	cluster.Bootstrap(regionID, []uint64{storeID}, []uint64{peerID}, peerID)
  	return
  }
docs: // BootstrapWithSingleStore initializes a Cluster with 1 Region and 1 Store.