code: func (t *Torrent) addrActive(addr string) bool {
  	if _, ok := t.halfOpen[addr]; ok {
  		return true
  	}
  	for c := range t.conns {
  		ra := c.remoteAddr
  		if ra.String() == addr {
  			return true
  		}
  	}
  	return false
  }
docs: // There's a connection to that address already.