int i);

// Get the name of the ith attribute.  output should have the size of
// TF_OperationGetAttrNameLength(oper, i).
TF_CAPI_EXPORT extern void TF_OperationGetAttrName(TF_Operation* oper, int i,
                                                   char* output,
                                                   TF_Status* status);

  ASSERT_EQ(1, TF_OperationGetNumAttrs(oper));
  ASSERT_EQ(1, TF_OperationGetAttrNameLength(oper, 0));

  std::unique_ptr<char[]> value(new char[1]);

  TF_OperationGetAttrName(oper, 0, value.get(), s_);
  EXPECT_EQ(TF_OK, TF_GetCode(s_)) << TF_Message(s_);
  EXPECT_EQ("v", string(static_cast<const char*>(value.get()), 1));
}

TEST_F(CApiAttributesTest, Errors) {