EXPECT_EQ(0, TF_OperationGetControlInputs(scalar, control_ops, 100));
  EXPECT_EQ(0, TF_OperationNumControlOutputs(scalar));
  EXPECT_EQ(0, TF_OperationGetControlOutputs(scalar, control_ops, 100));

  EXPECT_EQ(0, TF_OperationNumControlInputs(feed));
  EXPECT_EQ(0, TF_OperationGetControlInputs(feed, control_ops, 100));
  EXPECT_EQ(0, TF_OperationNumControlOutputs(feed));
  EXPECT_EQ(0, TF_OperationGetControlOutputs(feed, control_ops, 100));

// the graph.
TF_CAPI_EXPORT extern int TF_OperationNumControlOutputs(TF_Operation* oper);

// Get the list of operations that have `*oper` as a control input.
// `control_outputs` must point to an array of length at least
// `max_control_outputs` (ideally set to
// TF_OperationNumControlOutputs(oper)). Beware that a concurrent
// modification of the graph can increase the number of control