How to make add-apt-get repository to work behind proxy

First set the environment variable for https_proxy

export https_proxy=....

only setting of http_proxy is not enough.
And I needed to execute the add-apt-repository command as root, NOT via sudo.
Code:

sudo su
add-apt-repository ppa:........

Editing Grub2 the easy way

I found this link which is very useful if you want to edit grub in a graphical manner