// - Adding the default attributes to each node def if they are missing from
//   the GraphDef.
// - Replacing LegacyFedInput nodes with Placeholder nodes if
//   convert_legacy_fed_inputs option is enabled.
Status PreprocessGraphDef(const GraphImportConfig* specs, GraphDef* graph_def) {
  for (auto& node_def : *graph_def->mutable_node()) {
    // TODO(hinsu): Completely deprecate support for LegacyFedInput ops. One