TF_ImportGraphDefResults* results, int* num_opers, TF_Operation*** opers);

// Fetches any input mappings requested via
// TF_ImportGraphDefOptionsAddInputMapping() that didn't appear in the GraphDef
// and weren't used as input to any node in the imported graph def. The number
// of fetched mappings is returned in `num_missing_unused_input_mappings`. The

//
// Example:
//   void func() {
//     FILE* fp = fopen("data.txt", "r");
//     if (fp == nullptr) return;
//     auto fp_cleaner = gtl::MakeCleanup([fp] { fclose(fp); });
//     // No matter what, fclose(fp) will happen.
//     DataObject d;
//     while (ReadDataObject(fp, &d)) {
//       if (d.IsBad()) {
//         LOG(ERROR) << "Bad Data";
//         return;
//       }
//       PushGoodData(d);
//     }
//   }
//

  inline const cpp_impl *unwrap(const wrapper *w) {                            \
    return reinterpret_cast<const cpp_impl *>(w);                              \
  }                                                                            \
                                                                               \
  inline wrapper *wrap(cpp_impl *i) { return reinterpret_cast<wrapper *>(i); } \

/// method signatures to have some type of type safety: for example, operations
/// that are only valid on random access files have a `TF_RandomAccessFile`
/// argument.
///
/// Lifetime: The wrapper data structures are owned by core TensorFlow. The data
/// pointed to by the `void*` members is always owned by the plugin. The plugin
/// will provide functions to call to allocate and deallocate this data (see