Status status = op_ptr->Execute(temp_outputs, &num_retvals);
  *loss = temp_outputs[0];
  *backprop = temp_outputs[1];
  return status;
}

// Op: AccumulatorApplyGradient()
// Summary:
//
// Description:
Status AccumulatorApplyGradient(AbstractContext* ctx, AbstractTensorHandle** handle, AbstractTensorHandle* const local_step, AbstractTensorHandle* const gradient, const char* name, const char* raw_device_name) {

//
Status AccumulatorApplyGradient(AbstractContext* ctx, AbstractTensorHandle** handle, AbstractTensorHandle* const local_step, AbstractTensorHandle* const gradient, const char* name = nullptr, const char* raw_device_name = nullptr);

//

      "Neg",        // Simple unary Op
      "MatMul",     // 2 inputs & attrs with default values
      "IdentityN",  // Variadic input+output
      "SparseSoftmaxCrossEntropyWithLogits",  // 2 outputs
      "AccumulatorApplyGradient",             // 0 outputs
      "VarHandleOp",                          // type, shape, list(string) attrs
      "RestoreV2",  // Variadic output-only, list(type) attr
  };