code: def _determine_next_ott_id(self):
          
          if self._doc_counter_lock is None:
              self._doc_counter_lock = Lock()
          with self._doc_counter_lock:
              _LOG.debug('Reading "{}"'.format(self._id_minting_file))
              noi_contents = self._read_master_branch_resource(self._id_minting_file, is_json=True)
              if noi_contents:
                  self._next_ott_id = noi_contents['next_ott_id']
              else:
                  raise RuntimeError('Stored ottid minting file not found (or invalid)!')
docs: Read an initial value (int) from our stored counter (file)
  
          Checks out master branch as a side effect!