How do you exit vimdiff mode in vim, specifically, for Fugitive?

Question

I am using vim with the fugitive extension. It has a :Gdiff command which brings you into vimdiff mode, but what is the right/quick way to close/quit vimdiff mode?

I.e.,

Answer 1

this is what I have to leave the vimdiff windows after using :Gdiff

nnoremap gD :q! :Gedit!