tensorflow::AttrValue attr_value;
  ASSERT_TRUE(GetAttrValue(feed, "dtype", &attr_value, s)) << TF_Message(s);
  EXPECT_EQ(attr_value.type(), tensorflow::DT_INT32);

  // Test not found errors in TF_Operation*() query functions.
  EXPECT_EQ(-1, TF_OperationOutputListLength(feed, "bogus", s));
  EXPECT_EQ(TF_INVALID_ARGUMENT, TF_GetCode(s));

  ASSERT_FALSE(GetAttrValue(feed, "missing", &attr_value, s));