--- old/share/gc/g1/heapRegionSet.hpp	2018-06-14 13:09:51.512858381 -0700
+++ new/share/gc/g1/heapRegionSet.hpp	2018-06-14 13:09:51.480858380 -0700
@@ -192,7 +192,7 @@
   // Assumes that the list is ordered and will preserve that order. The order
   // is determined by hrm_index.
   inline void add_ordered(HeapRegion* hr);
-
+  inline HeapRegion* show_tail() { return _tail; }
   // Removes from head or tail based on the given argument.
   HeapRegion* remove_region(bool from_head);