void runOnOperation() override;
};

constexpr char kAliasingAttr[] = "tf.aliasing_output";
constexpr int kUnassigned = -1;

struct AliasInfo {
  AliasInfo() : input_index(kUnassigned), output_index(kUnassigned) {}
  int input_index;
  int output_index;
};

// Idenitfy tf_device.cluster_func input-output alias pairs.
// This is currently conservative, primarily handling the following base case:
// ```

                         int input_index, bool use_function,
                         AbstractTensorHandle** numerical_grad) {
  vector<AbstractTensorHandle*> theta_inputs(inputs.size());
  for (int i{}; i < inputs.size(); ++i) {
    theta_inputs[i] = inputs[i];
  }

  AbstractTensorHandle* theta =
      theta_inputs[input_index];  // parameter we are grad checking

    if (!outputs[i]) continue;

    AbstractTensorHandlePtr numerical_grad;
    {
      AbstractTensorHandle* numerical_grad_raw;
      s = CalcNumericalGrad(ctx, model, inputs,
                            /*input_index=*/i, use_function,
                            &numerical_grad_raw);
      ASSERT_EQ(errors::OK, s.code()) << s.message();
      numerical_grad.reset(numerical_grad_raw);
    }

    TF_Tensor* numerical_tensor;