code: func Filter(addrs []ma.Multiaddr) []ma.Multiaddr {
  	raddrs := make([]ma.Multiaddr, 0, len(addrs))
  	for _, addr := range addrs {
  		if isRelayAddr(addr) {
  			continue
  		}
  		raddrs = append(raddrs, addr)
  	}
  	return raddrs
  }
docs: // Filter filters out all relay addresses.