script to fetch the PR and switched to the right branch

pr.sh

#Create a bash in your ~/.bash_profile
# Do `source ~/.bash_profile` or reopen the console to make it work.
# Call `pr 1234` (1234 is the pull request number)
# the PR will be fetched and switched to the right branch

pr() {
  git fetch upstream pull/$1/head:pr-$1
  git checkout pr-$1
}