--- a/src/hotspot/share/classfile/classLoaderData.hpp	Thu Mar 15 07:20:32 2018 +0100
+++ b/src/hotspot/share/classfile/classLoaderData.hpp	Thu Mar 15 07:40:00 2018 -0400
@@ -205,6 +205,7 @@
     // However, multiple threads can execute oops_do concurrently with add.
     oop* add(oop o);
     bool contains(oop p);
+    NOT_PRODUCT(bool owner_of(oop* p);)
     void oops_do(OopClosure* f);
 
     int count() const;