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)


@Override
    public void writeBytes(ChannelBuffer src, int srcIndex, int length) {
        
        byte[] data = new byte[length];
        src.getBytes(srcIndex, data, 0, length);
        writeBytes(data, 0, length);
    }
    
    @Override
    public int writeBytes(InputStream src, int length) throws IOException {
        return buffer.writeBytes(src, length);
    }
    
    @Override
    public int writerIndex() {
        return buffer.writerIndex();
    }
    
    @Override
    public void writerIndex(int writerIndex) {
        buffer.writerIndex(writerIndex);
    }
    
    @Override
    public int compareTo(ChannelBuffer o) {
        return ChannelBuffers.compare(this, o);
    }
}