code: func (c *Configuration) RemoteBranchForLocalBranch(localBranch string) string {
  	// get remote ref to track, may not be same name
  	merge := c.Find(fmt.Sprintf("branch.%s.merge", localBranch))
  	if strings.HasPrefix(merge, "refs/heads/") {
  		return merge[11:]
  	} else {
  		return localBranch
  	}
  }
docs: // RemoteBranchForLocalBranch returns the name (only) of the remote branch that the local branch is tracking
  // If no specific branch is configured, returns local branch name