This op returns a scalar string tensor as a key for user to look for the loaded array
    and a future containing the restored tensor.
  }];

  let arguments = (ins
    TF_Tensor:$variable,
    DefaultValuedAttr<BoolAttr, "false">:$used_by_host
  );

  let results = (outs
    TF_Tensor:$array_key,
    MlrtFutureType: $tensor_future
  );
}

    Other ops executed by TFRT may make use of $tensor_future.
  }];

  let arguments = (ins
    Arg<TF_Tensor, [{The variable tensor to be loaded}], []>:$variable,
    DefaultValuedAttr<BoolAttr, "false">:$used_by_host
  );

  let results = (outs
    TF_StrTensor:$array_key,
    TF_Tensor: $tensor_future
  );

  TF_DerivedOperandTypeListAttr Tin = TF_DerivedOperandTypeListAttr<0>;

    The `tf.IfrtCall` kernel uses the output $array_key.
    Other ops executed by TFRT may make use of $tensor_future.
  }];

  let arguments = (ins
    TFTensorType:$variable,
    DefaultValuedAttr<BoolAttr, "false">:$used_by_host
  );

  let results = (outs
    TFTensorType:$array_key,
    MlrtFutureType: $tensor_future
  );
}