code: def _read_master_branch_resource(self, fn, is_json=False):
          
          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
docs: This will force the current branch to master!