https://www.graalvm.org/ 
public interface com.oracle.truffle.api.instrumentation.AllocationListener
  minor version: 0
  major version: 59
  flags: flags: (0x0601) ACC_PUBLIC, ACC_INTERFACE, ACC_ABSTRACT
  this_class: com.oracle.truffle.api.instrumentation.AllocationListener
  super_class: java.lang.Object
{
  public abstract void onEnter(com.oracle.truffle.api.instrumentation.AllocationEvent);
    descriptor: (Lcom/oracle/truffle/api/instrumentation/AllocationEvent;)V
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    MethodParameters:
       Name  Flags
      event  

  public abstract void onReturnValue(com.oracle.truffle.api.instrumentation.AllocationEvent);
    descriptor: (Lcom/oracle/truffle/api/instrumentation/AllocationEvent;)V
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    MethodParameters:
       Name  Flags
      event  
}
SourceFile: "AllocationListener.java"