prow/git/git.go
func (r *Repo) CheckoutNewBranch(branch string) error {
	r.logger.Infof("Create and checkout %s.", branch)
	co := r.gitCommand("checkout", "-b", branch)
	if b, err := co.CombinedOutput(); err != nil {
		return fmt.Errorf("error checking out %s: %v. output: %s", branch, err, string(b))
	}
	return nil
}
func (r *Repo) CheckoutNewBranch(branch string) error {
	r.logger.Infof("Create and checkout %s.", branch)
	co := r.gitCommand("checkout", "-b", branch)
	if b, err := co.CombinedOutput(); err != nil {
		return fmt.Errorf("error checking out %s: %v. output: %s", branch, err, string(b))
	}
	return nil
}
// CheckoutNewBranch creates a new branch and checks it out.