code: public static List<GatewayAddress> asListFromDomain(final String domainAddress) {
          if (domainAddress == null) {
              throw new IllegalArgumentException("domain address must not be null");
          }
  
          GatewayAddress domain = new GatewayAddress(0, domainAddress);
          InetAddress[] addresses;
          try {
              addresses = InetAddress.getAllByName(domain.getHost());
          } catch (Exception e) {
              throw new IllegalArgumentException("invalid domain '" + domain + "' " + e.getMessage());
          }
  
          List<GatewayAddress> list = new ArrayList<GatewayAddress>();
          int id = 1;
          for (InetAddress address : addresses) {
              list.add(new GatewayAddress(id++, address.getHostAddress(), domain.getPort()));
          }
  
          return list;
      }
docs: As list from domain.
  
  @param domainAddress the domain address
  @return the list