docs: def _ForemanOp(self):
      """Sends Foreman checks periodically."""
      period = config.CONFIG["Client.foreman_check_frequency"]
      self._threads["Worker"].SendReply(
          rdf_protodict.DataBlob(),
          session_id=rdfvalue.FlowSessionID(flow_name="Foreman"),
          require_fastpoll=False)
      time.sleep(period)