// variables.
//
// The returned TF_WhileParams will have all fields initialized except
// `cond_output`, `body_outputs`, and `name`. The `body_outputs` buffer will be
// allocated to size `ninputs`. The caller should build `cond_graph` and
// `body_graph` starting from the inputs, and store the final outputs in
// `cond_output` and `body_outputs`.
//
// If `status` is OK, the caller must call either TF_FinishWhile or

    s->status = InvalidArgument("TF_WhileParams `cond_output` field isn't set");
    return false;
  }
  for (int i = 0; i < params.ninputs; ++i) {
    if (params.body_outputs[i].oper == nullptr) {
      s->status = InvalidArgument("TF_WhileParams `body_outputs[", i, "]` ",
                                  "field isn't set");
      return false;
    }
  }
  if (params.name == nullptr) {