code: func prioritizePeers(peers []fab.Peer) selectopts.PrioritySelector {
  	return func(peer1, peer2 fab.Peer) int {
  		hasPeer1 := containsPeer(peers, peer1)
  		hasPeer2 := containsPeer(peers, peer2)
  
  		if hasPeer1 && hasPeer2 {
  			return 0
  		}
  		if hasPeer1 {
  			return 1
  		}
  		if hasPeer2 {
  			return -1
  		}
  		return 0
  	}
  }
docs: // prioritizePeers is a priority selector that gives priority to the peers that are in the given set