code: private static void onDataRead(ChannelHandlerContext ctx, Http2DataFrame data) throws Exception {
          Http2FrameStream stream = data.stream();
  
          if (data.isEndStream()) {
              sendResponse(ctx, stream, data.content());
          } else {
              // We do not send back the response to the remote-peer, so we need to release it.
              data.release();
          }
  
          // Update the flowcontroller
          ctx.write(new DefaultHttp2WindowUpdateFrame(data.initialFlowControlledBytes()).stream(stream));
      }
docs: If receive a frame with end-of-stream set, send a pre-canned response.