code: def _get_state(wallet_name: str) -> _STATE:
          
  
          dir_sentinel = RevRegBuilder.dir_tails_sentinel(wallet_name)
          file_pid = join(dir_sentinel, '.pid')
          file_start = join(dir_sentinel, '.start')
          file_stop = join(dir_sentinel, '.stop')
  
          if isfile(file_stop):
              return _STATE.STOPPING
  
          if isfile(file_start) or isfile(file_pid):
              return _STATE.RUNNING
  
          return _STATE.ABSENT
docs: Return current state of revocation registry builder process.
  
          :param wallet_name: name of wallet for corresponding Issuer
          :return: current process state as _STATE enum