command line – How to get the gpg key for a repository?

When adding a repository through add-apt-repository a new gpg key will be add.

e,g:

sudo add-apt-repository ppa:some-ppa

You will be asked to press Enter to import the gpg key. I need to get the gpg key for ppa:some-ppa without executing add-apt-repository.

Is it possible to get the gpg key before adding the repository (before executing add-apt-repository) from command line.