@Override
    public int readableBytes() {
        return byteBuf.readableBytes();
    }
@author <a href="mailto:zhanggeng.zg@antfin.com">GengZhang</a>
@since 5.4.0
remoting/remoting-http/src/main/java/com/alipay/sofa/rpc/transport/netty/NettyByteBuffer.java