Make NewCommonAttributes public

category.go

@@ -16,7 +16,7 @@ type Category struct {
 // NewCategory creates a new Category. It returns a *Category.
 func NewCategory(term string) *Category {
 	return &Category{
-		CommonAttributes: newCommonAttributes(),
+		CommonAttributes: NewCommonAttributes(),
 		Term:             term,
 	}
 }