code: def CheckClientLabels(client_id,
                        labels_whitelist=None,
                        labels_owners_whitelist=None,
                        token=None):
    
  
    labels_whitelist = labels_whitelist or []
    labels_owners_whitelist = labels_owners_whitelist or []
  
    if data_store.RelationalDBEnabled():
      labels = data_store.REL_DB.ReadClientLabels(str(client_id))
    else:
      with aff4.FACTORY.Open(
          client_id.ToClientURN(), aff4_type=aff4_grr.VFSGRRClient,
          token=token) as fd:
        labels = fd.GetLabels()
  
    for label in labels:
      if (label.name in labels_whitelist and
          label.owner in labels_owners_whitelist):
        return
  
    raise access_control.UnauthorizedAccess(
        "Client %s doesn't have necessary labels." % utils.SmartStr(client_id))
docs: Checks a given client against labels/owners whitelists.