TFE_DeleteOp(op);
  if (TF_GetCode(status) != TF_OK) return nullptr;
  CHECK_EQ(1, num_retvals);
  TF_DeleteStatus(status);
  return var_handle;
}

TFE_TensorHandle* CreateVariable(TFE_Context* ctx, float value,
                                 const tensorflow::string& device_name,
                                 const tensorflow::string& variable_name) {
  TF_Status* status = TF_NewStatus();