hi,I see the  code for method setBytes in class com.alibaba.dubbo.remoting.transport.netty4.NettyBackedChannelBuffer.java which is below,is there a problem ?

![image](https://user-images.githubusercontent.com/20593632/46648646-90eaba00-cbc8-11e8-896d-9a1d235d7e0b.png)


buffer.readBytes(data, 0, length);
        dst.setBytes(dstIndex, data, 0, length);
    }
    @Override
    public ChannelBuffer readBytes(int length) {
        return new NettyBackedChannelBuffer(buffer.readBytes(length));
    }
    @Override
    public void resetReaderIndex() {
        buffer.resetReaderIndex();
    }
    @Override
    public void resetWriterIndex() {
        buffer.resetWriterIndex();
    }
    @Override
    public int readerIndex() {
        return buffer.readerIndex();
    }
    @Override
    public void readerIndex(int readerIndex) {
        buffer.readerIndex(readerIndex);
    }
    @Override
    public void readBytes(OutputStream dst, int length) throws IOException {
        buffer.readBytes(dst, length);
    }
    @Override
    public void setBytes(int index, byte[] src) {
        buffer.setBytes(index, src);