APT Behind PROXY with Password PROTECTION

Here how to get repository via proxy with password protection:

$sudo pico /etc/apt/apt.conf

then add :

Acquire::http::Proxy "http://username:password@proxyserver:port"

change username, password, proxyserver and port as you need, example

Acquire::http::Proxy "http://myname:mypassword@127.0.0.1:8080"

Save and continue to update repository

$sudo apt-get update