### Question:
Http2MultiplexCodec extends Http2FrameCodec { @Override final void onHttp2Frame(ChannelHandlerContext ctx, Http2Frame frame) { if (frame instanceof Http2StreamFrame) { Http2StreamFrame streamFrame = (Http2StreamFrame) frame; onHttp2StreamFrame(((Http2MultiplexCodecStream) streamFrame.stream()).channel, streamFrame); } else if (frame instanceof Http2GoAwayFrame) { onHttp2GoAwayFrame(ctx, (Http2GoAwayFrame) frame); ctx.fireChannelRead(frame); } else if (frame instanceof Http2SettingsFrame) { Http2Settings settings = ((Http2SettingsFrame) frame).settings(); if (settings.initialWindowSize() != null) { initialOutboundStreamWindow = settings.initialWindowSize(); } ctx.fireChannelRead(frame); } else { ctx.fireChannelRead(frame); } } Http2MultiplexCodec(Http2ConnectionEncoder encoder,
                        Http2ConnectionDecoder decoder,
                        Http2Settings initialSettings,
                        ChannelHandler inboundStreamHandler); @Override final void handlerAdded0(ChannelHandlerContext ctx); @Override final void handlerRemoved0(ChannelHandlerContext ctx); @Override final void channelReadComplete(ChannelHandlerContext ctx); @Override final void channelRead(ChannelHandlerContext ctx, Object msg);  }### Answer:
@Test public void unhandledHttp2FramesShouldBePropagated() { assertThat(parentChannel.readInbound(), instanceOf(Http2SettingsFrame.class)); Http2PingFrame pingFrame = new DefaultHttp2PingFrame(0); codec.onHttp2Frame(pingFrame); assertSame(parentChannel.readInbound(), pingFrame); DefaultHttp2GoAwayFrame goAwayFrame = new DefaultHttp2GoAwayFrame(1, parentChannel.alloc().buffer().writeLong(8)); codec.onHttp2Frame(goAwayFrame); Http2GoAwayFrame frame = parentChannel.readInbound(); assertSame(frame, goAwayFrame); assertTrue(frame.release()); }
@Test public void unhandledHttp2FramesShouldBePropagated() { assertThat(parentChannel.readInbound(), instanceOf(Http2SettingsFrame.class)); Http2PingFrame pingFrame = new DefaultHttp2PingFrame(0); codec.onHttp2Frame(pingFrame); assertSame(parentChannel.readInbound(), pingFrame); DefaultHttp2GoAwayFrame goAwayFrame = new DefaultHttp2GoAwayFrame(1); codec.onHttp2Frame(goAwayFrame); assertSame(parentChannel.readInbound(), goAwayFrame); }