const char* label1, const char* label2);

// -----------------------------------------------------------------------------
// Monitoring Sampler APIs.
// These APIs de-templated monitoring Sampler for swig.

typedef struct TFE_MonitoringSamplerCell TFE_MonitoringSamplerCell;

// Atomically add the value of the cell.
TF_CAPI_EXPORT extern void TFE_MonitoringSamplerCellAdd(

      std::unique_ptr<tensorflow::monitoring::Buckets> buckets,
      const char* description, LabelDesc&&... label) {
    sampler = absl::WrapUnique(tensorflow::monitoring::Sampler<NumLabels>::New(
        {name, description, label...}, std::move(buckets)));
  }

  std::unique_ptr<tensorflow::monitoring::Sampler<NumLabels>> sampler;
};

struct TFE_MonitoringSampler0 : TFE_MonitoringSampler<0> {

#include "tensorflow/core/common_runtime/eager/attr_builder.h"

namespace tensorflow {
namespace gradients {

// =============== Experimental C++ API for computing gradients ===============

// Sample gradient function:
//
// class AddGradientFunction : public GradientFunction {
//  public:
//   Status Compute(Context* ctx,
//                  absl::Span<AbstractTensorHandle* const> grad_inputs,