How can I fetch an unmerged pull request for a branch I don't own?

Question

I need to pull in a specific pull request (that hasn\'t been processed into the main stream yet) in the NServiceBus repo:

https://github.com/johnsimons/NServiceBus/c

Answer 1

Github has clear doc for merging the pull request into a local repo:

https://help.github.com/en/articles/checking-out-pull-requests-locally

It boils down to knowing that a pull request in GitHub is just a branch in the base repo where the branch name is a sequence number. The above article shows you how to find this number and the git command line magic to pull it into your local repo with whatever branch name you'd like.

I could not find a similarly simple way to merge the pull request into a fork I created on GitHub.