How localy merge Github Pull Request

Follow this commands for merge PR with favors the foreign merging tree in conflict resolution:

PR=25
USER_BRANCH='username:branch'
git checkout master
git pull origin master
git fetch origin pull/$PR/head:$PR
git merge -X theirs $PR -m 'Merge pull request #'"$PR"' from '"$USER_BRANCH"''
git push origin master
git branch $PR -d