--- old/src/hotspot/share/gc/parallel/adjoiningGenerationsForHeteroHeap.hpp	2018-10-03 14:40:21.621881800 -0700
+++ new/src/hotspot/share/gc/parallel/adjoiningGenerationsForHeteroHeap.hpp	2018-10-03 14:40:20.578710400 -0700
@@ -38,27 +38,27 @@
     return _total_size_limit;
   }
 
-  // HeteroVirtualSpaces creates non-overlapping virtual spaces.
-  // low() manages memory in nv-dimm and is meant for old generation.
-  // high() manages memory in dram and is meant for young generation.
+  // HeteroVirtualSpaces creates non-overlapping virtual spaces. Here _low and _high do not share a reserved space, i.e. there is no boundary
+  // separating the two virtual spaces.
   class HeteroVirtualSpaces : public AdjoiningVirtualSpaces {
-    PSVirtualSpace*    _young_vs;
-    PSVirtualSpace*    _old_vs;
-
     size_t _min_old_byte_size;
     size_t _min_young_byte_size;
     size_t _max_old_byte_size;
     size_t _max_young_byte_size;
     size_t _max_total_size;
 
+    // Internally we access the virtual spaces using these methods. It increases readability, since we were not really 
+    // dealing with adjoining virtual spaces separated by a boundary as is the case in base class.
+    // Externally they are accessed using low() and high() methods of base class.
+    PSVirtualSpace* young_vs() { return high(); }
+    PSVirtualSpace* old_vs() { return low(); }
+
   public:
     HeteroVirtualSpaces(ReservedSpace rs,
                         size_t min_old_byte_size,
                         size_t min_young_byte_size, size_t max_total_size,
                         size_t alignment);
 
-    PSVirtualSpace* high() { return _young_vs; }
-    PSVirtualSpace* low() { return _old_vs; }
     // Increase old generation size and decrease young generation size by same amount
     bool adjust_boundary_up(size_t size_in_bytes);
     // Increase young generation size and decrease old generation size by same amount