code: public alluxio.grpc.TtlAction getTtlAction() {
      alluxio.grpc.TtlAction result = alluxio.grpc.TtlAction.valueOf(ttlAction_);
      return result == null ? alluxio.grpc.TtlAction.DELETE : result;
    }
docs: <code>optional .alluxio.grpc.TtlAction ttlAction = 22;</code>