code: private void onDataRead(int streamId, ByteBuf data, int padding, boolean endOfStream) {
      flowControlPing().onDataRead(data.readableBytes(), padding);
      NettyClientStream.TransportState stream = clientStream(requireHttp2Stream(streamId));
      stream.transportDataReceived(data, endOfStream);
      if (keepAliveManager != null) {
        keepAliveManager.onDataReceived();
      }
    }
docs: Handler for an inbound HTTP/2 DATA frame.