@@ -124,7 +124,8 @@ class NCEOpMaker : public framework::OpProtoAndCheckerMaker {
"This attribute only be used in unitest. Classes "
"in this list wiil be used as negative classes "
"for every samples. Under normal conditions, "
"user should avoid setting this attribute.");
"user should avoid setting this attribute.")
.SetDefault({});
AddComment(R"DOC(
Compute and return the noise-contrastive estimation training loss.
See [Noise-contrastive estimation: A new estimation principle for unnormalized statistical models](http://www.jmlr.org/proceedings/papers/v9/gutmann10a/gutmann10a.pdf).