ASSERT_TRUE(TF_GraphOperationByName(graph, "feed") != nullptr);
  TF_Operation* oper = ScalarConst(3, graph, s);
  ASSERT_EQ(TF_OK, TF_GetCode(s)) << TF_Message(s);
  ASSERT_TRUE(TF_GraphOperationByName(graph, "scalar") != nullptr);
  Neg(oper, graph, s);
  ASSERT_EQ(TF_OK, TF_GetCode(s)) << TF_Message(s);
  ASSERT_TRUE(TF_GraphOperationByName(graph, "neg") != nullptr);

  // Export to a GraphDef.

                                                   TF_Status* status);

// Returns the operation in the graph with `oper_name`. Returns nullptr if
// no operation found.
TF_CAPI_EXPORT extern TF_Operation* TF_GraphOperationByName(
    TF_Graph* graph, const char* oper_name);

// Iterate through the operations of a graph.  To use:
// size_t pos = 0;
// TF_Operation* oper;