return -1;
  }
  return iter->second.second - iter->second.first;
}

int TF_OperationNumInputs(TF_Operation* oper) {
  return oper->node.num_inputs();
}

TF_DataType TF_OperationInputType(TF_Input oper_in) {
  return static_cast<TF_DataType>(oper_in.oper->node.input_type(oper_in.index));
}

int TF_OperationInputListLength(TF_Operation* oper, const char* arg_name,