@Test
    public void testTcpDecodeIllegalPacket1() {
        Codec codec = mock(Codec.class);
        doThrow(TRpcException.newFrameException(ErrorCode.TRPC_CLIENT_DECODE_ERR, "the request protocol is not trpc"))
                .when(codec).decode(any(), any());


        ProtocolConfig protocolConfig = new ProtocolConfig();
        // set batchDecoder true
        protocolConfig.setBatchDecoder(true);
        NettyCodecAdapter nettyCodecAdapter = NettyCodecAdapter.createTcpCodecAdapter(codec, protocolConfig);

        ChannelHandler decoder = nettyCodecAdapter.getDecoder();
        EmbeddedChannel embeddedChannel = new EmbeddedChannel();
        embeddedChannel.pipeline().addLast(decoder);

        ByteBuf byteBuf = AbstractByteBufAllocator.DEFAULT.heapBuffer();
        byteBuf.writeBytes("testTcpDecodeIllegalPacket1".getBytes(StandardCharsets.UTF_8));

        // write illegal packet
        EmbeddedChannel tmpEmbeddedChannel = embeddedChannel;
        DecoderException decoderException = Assert.assertThrows(DecoderException.class, () -> {
            tmpEmbeddedChannel.writeInbound(byteBuf);
        });

        Assert.assertTrue(decoderException.getCause() instanceof TRpcException);

        TRpcException tRpcException = (TRpcException) decoderException.getCause();
        Assert.assertEquals(tRpcException.getCode(), ErrorCode.TRPC_CLIENT_DECODE_ERR);

        Assert.assertEquals(byteBuf.refCnt(), 0);
    }