--- old/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/linux/LinuxDebugger.java	2019-11-01 17:51:55.629518900 +0900
+++ new/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/linux/LinuxDebugger.java	2019-11-01 17:51:54.996642100 +0900
@@ -57,6 +57,7 @@
   public List         getThreadList();
   public List         getLoadObjectList();
   public ClosestSymbol lookup(long address);
+  public String demangle(String sym);
 
   // NOTE: this interface implicitly contains the following methods:
   // From the Debugger interface via JVMDebugger