protected void decode(ChannelHandlerContext context, ByteBuf buffer) throws Exception {
   ChannelPipeline pipeline = context.pipeline();
   if (detectSsl && SslHandler.isEncrypted(buffer)) {
     SSLEngine engine = SSL_SERVER_CONTEXT.getValue().createSSLEngine();
     engine.setUseClientMode(false);
     pipeline.addLast(
         new SslHandler(engine),
         new ChunkedWriteHandler(),
         new PortUnificationServerHandler(delegatingHttpRequestHandler, false, detectGzip));
   } else {
     int magic1 = buffer.getUnsignedByte(buffer.readerIndex());
     int magic2 = buffer.getUnsignedByte(buffer.readerIndex() + 1);
     if (detectGzip && magic1 == 31 && magic2 == 139) {
       pipeline.addLast(
           new JZlibEncoder(ZlibWrapper.GZIP),
           new JdkZlibDecoder(ZlibWrapper.GZIP),
           new PortUnificationServerHandler(delegatingHttpRequestHandler, detectSsl, false));
     } else if (isHttp(magic1, magic2)) {
       NettyUtil.initHttpHandlers(pipeline);
       pipeline.addLast(delegatingHttpRequestHandler);
       if (BuiltInServer.LOG.isDebugEnabled()) {
         pipeline.addLast(
             new ChannelOutboundHandlerAdapter() {
               @Override
               public void write(
                   ChannelHandlerContext context, Object message, ChannelPromise promise)
                   throws Exception {
                 if (message instanceof HttpResponse) {
                   //                BuiltInServer.LOG.debug("OUT HTTP:\n" + message);
                   HttpResponse response = (HttpResponse) message;
                   BuiltInServer.LOG.debug(
                       "OUT HTTP: "
                           + response.getStatus().code()
                           + " "
                           + response.headers().get("Content-type"));
                 }
                 super.write(context, message, promise);
               }
             });
       }
     } else if (magic1 == 'C' && magic2 == 'H') {
       buffer.skipBytes(2);
       pipeline.addLast(new CustomHandlerDelegator());
     } else {
       BuiltInServer.LOG.warn("unknown request, first two bytes " + magic1 + " " + magic2);
       context.close();
     }
   }
   // must be after new channels handlers addition (netty bug?)
   ensureThatExceptionHandlerIsLast(pipeline);
   pipeline.remove(this);
   context.fireChannelRead(buffer);
 }
 @NotNull
 public static BuiltInServer start(
     @NotNull EventLoopGroup eventLoopGroup,
     boolean isEventLoopGroupOwner,
     int firstPort,
     int portsCount,
     boolean tryAnyPort,
     @Nullable NotNullProducer<ChannelHandler> handler)
     throws Exception {
   ChannelRegistrar channelRegistrar = new ChannelRegistrar();
   ServerBootstrap bootstrap = NettyUtil.nioServerBootstrap(eventLoopGroup);
   configureChildHandler(bootstrap, channelRegistrar, handler);
   int port = bind(firstPort, portsCount, tryAnyPort, bootstrap, channelRegistrar);
   return new BuiltInServer(eventLoopGroup, port, channelRegistrar, isEventLoopGroupOwner);
 }