--- old/src/hotspot/share/gc/g1/g1HeapSizingPolicy.hpp	2020-01-03 17:56:50.763828289 +0800
+++ new/src/hotspot/share/gc/g1/g1HeapSizingPolicy.hpp	2020-01-03 17:56:50.765828361 +0800
@@ -57,6 +57,9 @@
   // Clear ratio tracking data used by expansion_amount().
   void clear_ratio_check_data();
 
+  // Check if heap size can be shrinked
+  bool can_shrink_heap_size_to(size_t heap_size);
+
   static G1HeapSizingPolicy* create(const G1CollectedHeap* g1h, const G1Analytics* analytics);
 };