brep@X220i:~$ sudo snap install code --classic error: unable to contact snap store
snap 安装软件时报错，需要设置代理：
sudo snap set system proxy.https="http://127.0.0.1:8889" sudo snap set system proxy.http="http://127.0.0.1:8889"
然后可以正常安装：
brep@X220i:~$ sudo snap install code --classic code 08a217c4 from Visual Studio Code (vscode✓) installed