Graphviz dot kernel

 cf: https://github.com/laixintao/jupyter-dot-kernel

1. chiao@kpchiao9600k-2204:~$ . .bashrc_anaconda
2. (base) chiao@kpchiao9600k-2204:~$ pip install dot_kernel
   
3. (base) chiao@kpchiao9600k-2204:~$ install-dot-kernel
4. Done.
5. In jupyter lab, open with dot kernel: Launcher -> Dot
6. Edit the dot source in code cell and run.
7. Shift right click mouse on image (Yes! need to press Shift key!). 
8. Select "另存圖片" or "在新分頁中開啟圖片" 

Open in LibreOffice Draw:

1. Export dot as svg, say a.svg by
   dot -Tsvg -o a.svg a.dot
   
2. Insert image a.svg in draw
3. Right click the image, and select 斷開
4. All objects can be edited now