code: private void npnReceived(ServerHello mesg) throws IOException
      {
          NextProtoNegoExtension extension = (NextProtoNegoExtension)mesg.extensions.get(ExtensionType.EXT_NEXT_PROTOCOL_NEGOTIATION);
          if (extension != null)
          {
              protocols = extension.getProtocols();
              if (NextProtoNego.debug)
                  System.err.println(new StringBuilder("[C] NPN protocols ").append(protocols).append(" received from server for ").append(conn != null ? conn : engine));
          }
          else
          {
              if (NextProtoNego.debug)
                  System.err.println(new StringBuilder("[C] NPN protocols not sent by server for ").append(conn != null ? conn : engine));
          }
      }
docs: NPN_CHANGES_BEGIN