docs: def retrieve(run_id, det_id, outfile=None):
      """Retrieve run from iRODS for a given detector (O)ID"""
      try:
          det_id = int(det_id)
      except ValueError:
          pass
      path = irods_filepath(det_id, run_id)
      suffix = '' if outfile is None else outfile
      os.system("iget -Pv {0} {1}".format(path, suffix))