This will force the current branch to master!

def _read_master_branch_resource(self, fn, is_json=False):
        """This will force the current branch to master! """
        with self._master_branch_repo_lock:
            ga = self._create_git_action_for_global_resource()
            with ga.lock():
                ga.checkout_master()
                if os.path.exists(fn):
                    if is_json:
                        return read_as_json(fn)
                    with codecs.open(fn, 'rU', encoding='utf-8') as f:
                        ret = f.read()
                    return ret
                return None