code: func (oas *ObservedAddrSet) Addrs() (addrs []ma.Multiaddr) {
  	oas.RLock()
  	defer oas.RUnlock()
  
  	if len(oas.addrs) == 0 {
  		return nil
  	}
  
  	now := time.Now()
  	for _, observedAddrs := range oas.addrs {
  		for _, a := range observedAddrs {
  			if now.Sub(a.LastSeen) <= oas.ttl && a.activated(oas.ttl) {
  				addrs = append(addrs, a.Addr)
  			}
  		}
  	}
  	return addrs
  }
docs: // Addrs return all activated observed addresses